A peek inside the US Naval Observatory – keepers of time and celestial motion

(Today’s guest post comes to us from Carrie Fitzgerald, a professor of astronomy at Montgomery College in Maryland. She directs the Montgomery College Observatory; this piece originally ran on her blog.)

Driving past the woodsy grounds of the US Naval Observatory on Massachusetts Avenue, you can’t help but notice the prominent “USNO Master Clock” displaying the time in bright red digits. That is part of their mission, after all, to “determine the positions and motions of celestial bodies, motions of the Earth, and precise time.”

How exactly do they do what they do? And who are these modern day keepers of time and celestial motion?

In the physics and engineering department at MC, we are particularly lucky to have Amy Fredericks as an adjunct astronomy professor, teaching the evening section of our Astronomy 101 course. Not only is Amy a dedicated and enthusiastic instructor, she is also a real live astronomer at the US Naval Observatory!

For students who have wondered how I set the times of the Observatory Open House nights (I base it on when civil twilight ends), or how I know how much of the Moon’s visible disk is illuminated (81% last open house), well, I owe it all to Amy and the USNO Data Services. :) If I were a leprechaun, the data services portion of the USNO website would be the pot of gold at the end of the rainbow. It’s even better though, because the data services page is super easy to find.

Have you ever wanted to know more about what goes on inside the USNO and what goes into maintaining something as complex as the data services? Amy was generous enough to satisfy our curiosity about what she does during the daylight hours.

Q. I know you as our brilliant and intrepid evening astronomy instructor at Montgomery College, but you have a whole other life at the US Naval Observatory. How long have you been there, and what do you do?
A. I have worked at USNO for 6 years, in the Astronomical Applications Department. You could say I’m both an astronomer and a computer programmer. My department, working in concert with Her Majesty’s Nautical Almanac Office in the UK, produces the Astronomical, Nautical, and Air Almanacs. I work in the AA Department’s Software Products Division, which produces software and web applications related to the almanacs and also astrometry and celestial navigation.

I maintain the web applications and assist in the testing and maintenance of all our software products. Our website is http://aa.usno.navy.mil/.

Q. Is there a typical day for you at work? If so, what is it like?
A. A typical day may include making updates to our website or our data services, attending status meetings on the latest upgrade to one of products, or helping to get that upgrade ready by testing it.

Q. The USNO in Washington, DC has telescopes. What kind of telescopes do you have and what are they used for?
A. The biggest telescope we have in DC is the 26-inch refractor. It is the telescope that Asaph Hall used in 1877 at our old Foggy Bottom location to discover the moons of Mars. It is still used today (despite DC’s light pollution!) to study double stars and the moons of the outer planets. We have a few smaller telescopes that are also used for research.
Our “dark sky” site is USNO’s Flagstaff Station in Arizona. That’s where we have some big reflecting telescopes that are used for viewing fainter objects than we can see from DC. One of them was used to discover Charon, the biggest moon of Pluto, in the 1970s.

Q. What is your favorite thing about being at the USNO?
A. Our products are used by the military, the scientific community, and the public. I love being able to support all of our users. And, of course, I love the people I work with at the Observatory.

Q. Are you ever able to bring what you do at the USNO into the classroom?
A. Sometimes I make passing references to it but not too much. I’m always trying to think of ways! I know friends at other colleges have assigned their students to use our website in their homework.

Q. The USNO is also the official residence of the vice president, so I have to ask…in all the time you’ve been at the USNO, any vice president sightings?
A. Sadly, no! Just his helicopter and motorcade on occasion. He does use our library for news interviews, so the librarians probably see him the most.

Modern Astronomers

This edition of the Notable Women in Science series presents modern astronomers. Many of these women are currently working in fields of research or have recently retired. As before, pages could be written about each of these women, but I have limited information to a summary of their education, work, and selected achievements. Many of these blurbs have multiple links, which I encourage you to visit to read extended biographies and learn about their current research interests.

From L to R: Anne Kinney, NASA Goddard Space Flight Center, Greenbelt, Md.; Vera Rubin, Dept. of Terrestrial Magnetism, Carnegie Institute of Washington; Nancy Grace Roman Retired NASA Goddard; Kerri Cahoy, NASA Ames Research Center, Moffett Field, Calif.; Randi Ludwig. University of Texas, Austin, Texas.
Vera Cooper Rubin was making advancements decades ahead of popularity of her research topic.  She received her B.A. from Vassar College, M.A. from Cornell University, and her Ph.D. from Georgetown University in the 1940s and 50s. She continued at Georgetown University as a research astronomer then assistant professor, and then moved to the Carnegie Institution. Among her honors is her election to the National Academy of Sciences and receiving the National Medal of Science, Gold Medal of the Royal Astronomical Society. She was only the second female recipient of this medal, the first being Caroline Herschel. She has had an asteroid and the Rubin-Ford effect named after her. She is currently enjoying her retirement.

Dr. Nancy Roman
Nancy Grace Roman has a lifetime love for astronomy. She received her B.A. from Swarthmore College and Ph.D. from the University of Chicago in the 1940s. She started her career as a research associate and instructor at Yerkes Observatory, but moved on due to a low likelihood of tenure because of her gender. She eventually moved through chief and scientist positions to Head of the Astronomical Data Center at NASA. She was the first female to hold an executive position at NASA. She has received honorary D.Sc. from several colleges and has received several awards, including the American Astronautical Society’s William Randolf Lovelace II Award and the Women in Aerospace’s LIfetime Achievement Award. She is currently continuing to inspire young girls to dream big by consulting and lecturing by invitation at venues across the U.S.

Catharine (Katy) D. Garmany researches the hottest stars. Dr. Garmany earned her B.S. from Indiana University and her M.A. and Ph.D. from the University of Virginia in the 1960s and 70s. She continued with research and teaching at several academic institutions. She has served as past president of the Astronomical Society of the Pacific and received the Annie Jump Cannon Award. She is currently associated with the National Optical Astronomy Observatory with several projects.

Dr. Elizabeth Roemer
Elizabeth Roemer is a premier recoverer of “lost” comets. She received her B.A.  and Ph.D. from University of California – Berkeley in the 1950s. She spent some time as a researcher at U.S. Observatories before going to the University of Arizona and moving through the professorial ranks. She has received several awards, including Mademoiselle Merit Award, one of only four recipients of the Benjamin Apthorp Gould Prize from the National Academy of Sciences, and a NASA Special Award. She is currently Professor Emerita at the University of Arizona with research interests in comets and minor planets (“asteroids”), including positions (astrometry), motions, and physical characteristics, especially of those objects that approach the Earth’s orbit.

Margaret Joan Geller is a widely respected cosmologist. She received her A.B. from the University of California-Berkeley, and M.A. and Ph.D. from Princeton University in the 1970s. She moved through the professorial ranks at Harvard University and is currently an astrophysicist at the Smithsonian Astrophysical Observatory. Some of her awards include the MacArthur “Genius” Award and the James Craig Watson Award from the National Academy of Sciences. She continues to provide public education in science through written, audio, and video media.

In 1995, the majestic spiral galaxy NGC 4414 was imaged by the Hubble Space Telescope as part of the HST Key Project on the Extragalactic Distance Scale. An international team of astronomers, led by Dr. Wendy Freedman of the Observatories of the Carnegie Institution of Washington, observed this galaxy on 13 different occasions over the course of two months.


Wendy Laurel Freedman is concerned with the fundamental question”How old is the universe?”  She received her B.S., M.S., and Ph.D. from the University of Toronto in the 1970s and 80s. After earning her Ph.D. she joined Observatories of the Carnegie Institution in Pasadena, California as a postdoctoral fellow and became faculty a few years later, as the first woman to join the Observatory’s permanent scientific staff. She has received several awards and honors, among them the Gruber Cosmology Prize. Her current work is focusing on the Giant Magellan Telescope and the questions it will answer. 

Sandra Moore Faber researches the origin of the universe. Dr. Faber earned her B.A. from Swarthmore College and her Ph.D. from Harvard University in the 1960s and 70s. She joined the Lick Observatory at the University of California – Santa Cruz and moved through the Astronomer and Professorial rankings. Her achievements include being elected to the National Academy of Sciences, the Heineman Prize, a NASA Group Achievement Award, Harvard Centennial Medal, and the Bower Award. She continues to research the formation and evolution of galaxies and the evolution ofstructure in the universe.


Dr. Heidi Hammel

Heidi Hammel is known as an excellent science communicator, researcher, andleader. She earned her B.S. from Massachusetts Institute of Technology and Ph.D. from the University of Hawaii in the 1980s. At NASA she led the imaging team of the Voyager 2’s encounter with Neptune and became known for her science communication for it.  She returned to MIT as a scientist for nearly a decade. Among her honors, she has received Vladimir Karpetoff Award , Klumpke-Roberts Award, and the Carl Sagan Medal.  She is currently at the Space Science Institute with a research focused on ground- and space-based studies of Uranus and Neptune.


Judith Sharn Young was inspired by black holes. She earned her B.A. from Harvard University and her M.S. and Ph.D. from the University of Minnesota in the 1970s. She began her academic career at the University of Massachusetts – Amherst, proceeding through the professorial ranks. She has earned several honors, including the Annie Jump Cannon Prize, the Maria Goeppert-Mayer Award, and a Sloan Research Fellowship. She is currently teaching and researching galaxies and imaging at the University of Massachusetts. 


Jocelyn Bell Burnell is the discoverer of pulsars. She earned her B.Sc. from the University of Glasgow and her Ph.D. from Cambridge University in the 1960s. After her graduation, she worked at the University of Southampton in research and teaching, and continued to work in research positions at several institutions. She is well known for her discovery of pulsars, which earned her research advisor a Nobel Prize. Among her awards are the Albert A. Michelson Prize, Beatrice Tinsley Prize, Herschel Medal, Magellanic Premium, and Grote Reber Metal. She has received honorary doctorates from Williams College, Harvard University, and the University of Durham. She is currently Professor of Physics and Department Chair at the Open University, England. 



Awards Mentioned:
The National Academy of Sciences is composed of select scientists who are leaders in their fields.
The National Medal of Science is a presidential award given to physical, biological, mathematical, or engineering scientists who have contributed outstanding knowledge to their field. 
The Gold Medal of the Royal Astronomical Society is the society’s highest honor given in astronomy
American Astronautical Society’s William Randolf Lovelace II Award recognizes outstanding contributions to space science.
The Women in Aerospace’s Lifetime Achievement Award is given for contributions to aerospace science over a career spanning 25 years. 
The Annie Jump Cannon Award is given for outstanding research a doctoral student in astronomy with promise of future excellence. 
The Mademoiselle Merit Award was presented annually to young women showing the promise of great achievement.
The Benjamin Apthorp Gould Prize is given in recognition of scientific accomplishments by an American citizen. 
The NASA Special Award is given for exceptional work.
The MacArthur “Genius” Award is given to those who show exception merit and promise in creative work. 
The James Craig Watson Award is given for contributions in astronomy. 
The Gruber Cosmology Prize is given for fundamental advances in our understanding by a scientists. 
The Heineman Prize is given for outstanding work in the field of astrophysics. 
The NASA Group Achievement Award is given for accomplishment that advances NASA mission. 
The Harvard Centennial Medal is given to graduates of Harvard who have contributed to society upon graduation. 
The Bower Award is given for achievement in science. 
The Vladimir Karapetoff Award is given for outstanding technical achievement. 
The Klumpke-Roberts Award is given for enhancing public understanding and appreciation of astronomy. 
The Carl Sagan Medal is awarded for outstanding communication to the public about planetary science. 
The Maria Goeppert-Mayer Award is given to a female physicist for outstanding achievement in her early career. 
The Albert A. Michelson Prize is given for technical and professional achievement. 
The Beatrice Tinsley Prize is given for outstanding research contribution to astronomy or astrophysics. 
The Herschel Medal is given for investigations of outstanding merit in astrophysics.
The Magellanic Premium Medal is awarded for a discovery or invention advancing navigation or astronomy.


Much of the information for this post came from the book Notable Women in the Physical Sciences: A Biographical Dictionary edited by Benjamin F. Shearer and Barbara S. Shearer.

Adrienne M Roehrich, Double X Science Chemistry Editor

Historical Physicists

Featured today are 10 more women who broke boundaries by their presence in physics. They lived from 1711 to 2000. While I again limited information to one paragraph, I tried to highlight how they got their start, what universities, family members, and scientists were supportive of them. For these women, without the support of fathers, mothers, husbands, and mentors (all male with one exception) their life in science would not have happened. While barriers are not as difficult today as they were at the times these women made their way, it is a testament to what can be done when families and scientists support each other. These women are an inspiration and I hope you look up more information for them. In addition, I’d love to hear who your favorite women in science are in the comments.

Laura Bassi by Carlo Vandi 
Laura Bassi (1711-78) lectured on science until a few hoursbefore her death. An Italian scientist of international fame and one of the first women physicists in western history, Dr. Bassi earned her doctorate in philosophy and science through public debate from the University of Bologna. The University of Bologna offered Dr. Bassi a position in an effort to be known as a leader in women’s education. Unfortunately, this forward step was not acceptable to much of the rest of the world’s academic community and required stipulations to Dr. Bassi teaching. However, she countered these limitations with determination and passion. Her appointment to full membership in the Bendettini Academics also deterred some naysayers of Dr. Bassi’s involvement in research and teaching. In order to further her career, she married. A married woman could achieve more than a single woman at that time. Her death in 1778 was unexpected, especially as she had participated in an Academy of Sciences lecture on a few hours before.



If you can access the full article, I highly recommend The Desire to Contribute: AnEighteenth-Century Italian Woman of Science by Gabriella Berti Logan for more information on Laura Bassi.
Margaret Eliza Maltby (1860-1944) was a recognized scientistand advocate for women in science. She overcame the education offered to women by taking extra courses in order to attend Oberlin College and receive a B.A. She studied with the Art Students’ League in New York City to explore her interest in art and then taught high school before enrolling as a “special student” at the Massachusetts Institute of Technology (MIT), receiving her B.S. Oberlin recognized this extra effort by awarding Dr. Maltby an M.S. She became a physics instructor at Wellesley College. She was encouraged in her graduate students by an AAUW fellowship to attend Göttingen University, which culminated in Dr. Maltby being the first American woman to receive a Ph.D. in physics from any German university. Dr. Maltby worked as an instructor, a researcher, and administrator in many universities and colleges in the U.S. and abroad. Her stature as a scientist was acknowledged with her entry in the first edition of AmericanMen of Science. She also was active in the AAUW, advocating for women to gain education and enter scientific fields. After her retirement from university life, she maintained her interest in the arts.

Frederic and Irene Joliot-Cure by By James Lebenthal
Irène Joliot-Curie (1897-1956) was a Nobel Prize Laureate for “artificial radioactivity.”  Born to  the woman every person thinks of as the epitome of a woman in science, Marie Curie, Irène had an extremely close relationship with her paternal grandfather. Her schooling was outside of the standard schooling type, her first years at home and her latter years in a science and math heavy co-operative school of Madame Curie’s colleagues. She received her Bachelor’s degree from the Collège Sévigné and went on to study at the Sorbonne. She received her doctorate in 1925 based on work with her mother at the Radium Institute of the Sorbonne. She married Frédéric Joliot, another research assistant of Madame Curie’s. Dr. Joliot-Curie continued her research, interrupted by a stint as Undersecretary of State for Scientific Research, one of the first high government posts to be offered to a woman. She worked as a professor for the Sorbonne and director of the Radium Institute, but was not admitted to the Academy of Sciences due to discrimination despite her work. She died, like her mother, of acute leukemia. Her scientific work was complemented by her love of physical activity and motherhood.
Katharine Burr Blodgett By Smithsonian Institution, U.S.
Katharine Burr Blodgett (1898-1979) was a woman with an amazing number of firsts.  Born to a widow, she was a world citizen in her formative years, attended high school at a private school in New York City, won a scholarship to attend Bryn Mawr, and graduated second in her class there. She received her Master’s degree from the University of Chicago, then headed off to work with Nobel Laureate Irving Langmuir at General Electric (GE) and becoming the first woman research scientist there. She was able to work with Nobel Laureate Sir Ernest Rutherford and earn her Ph.D. from Cambridge University as the first woman to earn a doctorate from Cambridge. She returned to GE. During her career, she invented many applications and is credited with six patents. She achieved much when many women did not, but her work was de-valued in the media. She did earn recognition from her peers, including the ACS Garvan Medal, the Photographic Society of America Progress Medal, and a day named after her in her hometown of Schenectady, NY. In addition to her scientific life, she enjoyed gardening, civic engagement, acting, and “dart[ing] about Lake George in a fast motor boat.”
Astrophysicist Charlotte Emma Moore Sitterly (1898-1990) was an authority on sun composition. She started her career as an excellent student with extracurricular interests, attending Swarthmore College to earn her B.A. Upon graduation, she accepted a position as a mathematics computer at Princeton University Observatory, one of the few employment opportunities available to science inclined women at the time. A stint at the Mount Wilson Observatory led to results published a 1928 monograph which was considered the authoritative work on the solar spectrum for four decades. She received her Ph.D. from the University of California, Berkeley in 1931. Her work earned her the Annie J. Cannon Prize, Silver and Gold Medals from the Department of Commerce, and several honorary doctorates in the U.S. and abroad. She was the first woman elected foreign associate by the Royal Astronomical Society of London. Her enthusiasm for her work continued until her death.

Maria Goeppert-Mayer By Nobel Foundation
Nuclear Physicist Maria Goeppert-Mayer (1906-1972)  was the second woman to win the  physics NobelHer early education was public education for girls followed by a private school founded by suffragettes. Circumstances led Dr. Goeppert-Mayer to take her exiting exams a year early, passing them she attended the University of Göttingen for her college education in mathematics. She continued to study physics at the University of Göttingen, earning her Ph.D. in 1930. She also married that year. The couple moved to America in hopes of better career trajectory for Dr. Goeppert-Mayer. Finding a position was difficult. When she had her first child, she stayed home with her for one year, then returned to research. While her positions were always part-time and not well recognized, she grew a well-respected network of collaborators. This network led to work with Hans Jensen which won her the Nobel Prize, shared with Jensen. Her network also eventually led to a full professorship position after 20 years of volunteer work. During this time, her health began to fail. She persevered with her work, publishing her last paper in 1965. The American Physical Society established an award in her honor in1985
Gertrude Scharff Goldhaber (1911-1998) was a respected researcher. She grew up in a time in Germany where girls were expected to become schoolteachers. She had a fascination with numbers, and eventually studied physics at the University of Munich, receiving her PhD in 1935. She fled Germany during the rise of the Nazis due to being Jewish, arriving in the United States and becoming a citizen in 1944. She had a wide involvement in the various National Laboratories studying nuclear physics. She also maintained several committee positions in the science community. She was also a strong advocate for women in the science community, forming a Women in Science group at Brookhaven National Lab and supporting other similar groups elsewhere. After her retirement from research, she continued interests in the history of science, outdoor activities, and art.
The Chicago Pile One Team 
Physicist, Molecular Spectroscopist Leona Woods MarshallLibby (1919-1986) Leona Woods grew up on a farm and was known for her inexhaustible energy. She attained her B.S. in chemistry from the University of Chicago when she was only 19 years old, and earned her PhD 5 years later. She worked as the only woman and youngest member of the Chicago Metallurgical Laboratory, a secret war group led by Enrico Fermi who built the world’s first nuclear fission reactor during her graduate work. Dr. Woods’ expertise was essential to the undertaking. She married another member of her team. She hid her first pregnancy until 2 days before her son’s birth. She took one week off before returning to work. Childcare was provided by her mother and sometimes Fermi’s bodyguard, John Baudino. Dr. Marshall was encouraged by Fermi as a female physicist. In the late 1950s, Dr. Marshall was divorced from her husband, pursuing her own career. In the early 1960s, Dr. Marshall moved to Colorado to work and married Willard Libby. Her mind was always considering any number of problems from many angles. She worked up until her death and was honored posthumously for her work, along with Lise Meitner, Marie Curie, and Irene Joliot-Curie.
Chien-Shiung Wu 
Chien-Shiung Wu (1912-1997) was a foremost experimental physicist of modern eraShe was encouraged as a girl to pursue her schooling as far as possible. This led her to teaching training, which lacked science so she taught herself physics, chemistry, and mathematics. She graduated high school with the highest grades in her class, earning her a place at the National Central University in Nanjing. She taught and did research upon graduation, then moved to the United States to pursue graduate studies. She earned her Ph.D. from the University of California – Berkeley in 1940, four years after leaving China. She was known for her expertise in nuclear fission and was consulted by top scientists. Despite this, her gender and nationality hindered her finding appropriate employment due to discrimination on both accounts. She married and started a teaching career, although she missed research. Upon the recommendation of Ernest Lawrence, she received offers from several Ivy League schools who were not accepting female students at the time. She became Princeton’s first woman instructor at that time. She was offered several positions, including back in China, but chose to remain in the U.S. to raise her son. She was unable to return to China until 1973. She worked at Columbia for many decades and earned accolades for her work.

Xide Xie (1921-2000) is a woman in China who needs no introductionHer early life involved much moving due to war and ill health, during which she taught herself English, calculus, and physics. She graduated in 1942 with a degree from Xiamen University. She moved to the United States to receive her master’s degree from Smith College in 1949 and her Ph.D. in physics from M.I.T. in 1951. She married in England and returned to China, despite the political climate. She taught and did research at the prestigious Fudan University. During the Cultural Revolution of 1966-76, she was detained, publicly humiliated, and endured breast cancer. After this upheaval, she returned to Fudan University, growing the physics department and achieving more esteemed positions in the University and government. She had also remained connected to her family, caring for her husband through lengthy illness. Her achievements were internationally recognized.

Awards Mentioned

Benedettini Academics were a select group of scholars from the Academy of Sciences created and named for Pope Benedict XIV to conduct research and present it annually at Academy meetings. This appointment escalated the prestige of the scientist above that given by being a member of the Academy of Sciences.

American Association for University Women (AAUW): Margaret Maltby received the European Fellowship from the Association of Collegiate Alumnae, which became the AAUW. This fellowship was specifically intended to help American women pursue graduate studies to circumvent rules that did not allow women to enroll in coeducational universities or earn graduate degrees.

The Nobel Prize is an international award given in several fields. It is one of the most prestigious awards for scientists in the eyes of the public.

The Garvan Medal is an award from the American Chemical Society to recognize distinguished service to chemistry by women chemists.
The Photographic Society of AmericaProgress Medal recognized a person who has made an outstanding contribution to the progress of photography or an allied subject. 
Annie Jump Cannon Prize is given to a North American female astronomer in the early stages of her career for her distinguished contribution to the field.
Department of Commerce Silver Medal, Gold Medal are the highest honors granted by the department for distinguished and exceptional performance.


Much of the information for this post came from the book Notable Women in the Physical Sciences: A Biographical Dictionary edited by Benjamin F. Shearer and Barbara S. Shearer.
Images for this post came from Wikimedia Commons

Adrienne M Roehrich, Double X Science Chemistry Editor


Modern Chemists

Our next installment of notable women in science brings us to chemists. Many of these women were born in the early part of the 20thcentury and forged their paths in tough times. All are still inspiring others today. Presented in no particular order:

Catherine Clarke Fenselau is a pioneer in mass spectrometryBorn in 1939, her interested in science was apparent before her 10th grade. She was encouraged to attend a women’s college, which at the time gave what she called “a special opportunity for serious-minded young women.” She graduated from Bryn Mawr with her A.B. in chemistry in 1961. Her graduate work at Stanford introduced her to the technology she would become known for, receiving her Ph.D. in analytical chemistry in 1965. Dr. Fenselau and her husband took positions at the Johns Hopkins University Medical School, at which time she had two sons. Johns Hopkins was under a mandate to accept female students and have female faculty at the time. Dr. Fenselau was made aware of the disparity of the treatment of male and female faculty, when in the 1970s the equal opportunity laws came into effect and she received an unexplained 25% raise. Her research resided in mass spectrometry, specifically in its use in biology. She became known as an anti-cancer researcher. Dr. Fenselau spoke often to chemists about feminism and goals, such as equal pay, opening closed career opportunities to women, and achieving the bonuses often only awarded to men. She has worked as an editor on several scientific journals. Some of her awards include the Garvan Medal, Maryland Chemist Award, and NIH Merit Award. Having  proper help at work and at home, and having supportive mentors and spouse has helped her achieve her success.

Elizabeth Amy Kreiser Weisburger is considered a real-lifemedical sleuth. Born in 1924, Dr. Weisburger was one of 10 children and schooled at home for her early education. She received her B.S. in chemistry, cum laude, Phi Alpha Epsilon from Lebanon Valley College. She received her Ph.D. in organic chemistry in 1947 from the University of Cincinnati. She married and had three children. Her research has caused her to be proclaimed a pioneer in the field of chemical carcinogenesis. She balanced her busy life of working at the NCI, committee work, giving lectures, attending meetings, writing and reviewing papers while caring for children with the aid of housekeepers and nursery childcare. Some of her awards include the Garvan Medal and the HillebrandPrize. Her life philosophy is summed up with “Don’t take life so seriously; you’ll never get out of it alive.”

Helen M. Free, photo from the ACS
Helen M. Free is a major contributor to science and science education. Born in 1923, Ms. Free attended the College of Wooster, graduating with honors and a B.S. in 1944. In 1978, she earned a M.A. from Central Michigan University. In the meantime, she worked as a chemist at Miles Laboratories. She developed clinical effective and easy to use laboratory tests. She worked her way up through the company and also held an adjunct professor position at Indiana University, South Bend. Ms. Free has used her time to be active in professional societies and has served as president for the American Association for Clinical Chemistry and the American Chemical Society. Her awards include the Garvan Medal, a Distinguished Alumni Award from Wooster, and is the first recipient ofthe Public Outreach Award bearing her name.

Jeanette Grasselli Brown is an industry researcher and director. Born in 1929, she graduated summa cum laudewith her B.S. from Ohio University in 1950 and received her M.S. in 1958 from Western Reserve University. She worked at Standard Oil of Ohio (now BP of America), and became the first woman director of corporate research there. She has received numerous awards including the Garvan Medal, Ohio Women’s Hall of Fame, and the Fisher Award in Analytical Chemistry. She has published 75 papers in scientific journals, written 9 books, and received 7 honorary Doctorate of Science degrees. She is an activist for the future of women in science.

Jean’ne Marie Shreeve is an important fluorine chemist. Born in 1933, she encountered sexism through her mother’s inability to be employed despite her training as a schoolteacher. Dr. Shreeve graduated with a B.A. from Montana State University in 1953, followed by an M.S. in 1956 from the University of Minnesota, and a Ph.D. in inorganic chemistry in 1961 from the University of Washington. After graduating, she worked her way through the professorial ranks at the University of Idaho. Besides her own research, Dr. Shreeve has devoted herself to educating other chemists. Some of her awards include U.S. Ramsey Fellow, Alfred P. Sloan Fellow, and Garvan Medal.

Joyce Jacobon Kaufman by Smithsonian Institution 
Joyce Jacobson Kaufman is distinguished in many fields. Born in 1929, she was reading before the age of 2 and was a voracious reader as a child. This led to her reading the biography of Marie Curie, which inspired her to be a chemist. Dr. Kaufman received her B.S., M.A., and Ph.D. in physical chemistry from Johns Hopkins University in 1949, 1959, and 1960, respectively. She married and had a daughter. Her research in the application of quantum mechanics to chemistry, biology, and medicine led to her renown in several fields. She has also spent much time in service positions. Her awards include the Martin Company Gold Medal for Outstanding Scientific Accomplishments (received 3 times), the Garvan Medal, and honored as one of ten Outstanding Women in the State of Maryland.

Madeleine M. Joullie is known for elegant research and inspirational teachingBorn in 1927, her early life in Brazil was overly-protective, so her father encouraged her to attend school in the U.S.A. She received her B.Sc. from Simmons College in 1949, and her M.Sc. and Ph.D. in chemistry in 1950 and 1953, respectively, from the University of Pennsylvania. She then worked her way through the professorial ranks at the University of Pennsylvania. Initially, only the women graduate students would work with her, and they were few and far between. She has explored many research avenues over the course of her career. Her awards include the Garvan Medal, the American Cyanamid Faculty Award, the Henry HillAward, and the Lindback Award for Distinguished Teaching.

Marjorie Caserio is a researcher, educator, author, andacademic administrator. Born in 1929, she entered university with the goal of becoming a podiatrist in order to generic income. She received several rejections from colleges due to her gender, and eventually was accepted to be the only woman in her class. She received her B.S. from Chelsea College, University of London in 1950 and an M.A. and Ph.D from Bryn Mawr in 1951 and 1956. Dr. Caserio is co-author of one of the most popular organic chemistry textbooks in the chemistry during the 1960s and 1970s. Her awards include the Garvan Medal and John S. Guggenheim Foundation Fellow.

Mary Lowe Good has won several awards and is a public servant. Born in 1931, she was supported in her aspirations by her parents. She received her B.S. in 1950 from the University of Central Arkansas, which was then the Arkansas State Teachers College. She went on to receive her M.S. and Ph.D. in inorganic and radiochemistry from the University of Arkansas in 1953 and 1955. Her career began in academic, but an appointment to the National Science Foundation by President Carter changed the course of her career. She served the International Union of Pure and Applied Chemistry, and president of the American Chemical Society and Zonta International Foundation. Some of her awards include Garvan Medal, CharlesLathrop Parsons Award, and 18 honorary doctorates.

Ruth Mary Roan Benerito is an academic and government scientistBorn in 1916, she began college at the age of 15 at Sophie Newcomb College, the women’s college of Tulane and received her B.S. in 1935. She received her M.S. from Tulane University in 1938, which she worked half-time while working another job at the same time. She taught at Tulane and its colleges before going to the University of Chicago to get her Ph.D. in 1948 in physical chemistry, again working on a part-time basis. Her career oscillated between academia and industry, earning her a large number of awards, including the Federal Women’s Award, the Southern Chemist Award, and inducted as a Fellow into the American Institute of Chemists and Iota Sigma Pi.  

Awards

The Garvan Medal is an award from the American Chemical Society to recognize distinguished service to chemistry by women chemists.

The Maryland Chemist Award recognizes and honors its members for outstanding achievement in the fields of chemistry.

The NIH Merit Award is a symbol of scientific achievement in the research community.

The Hillebrand Prize is awarded for original contributions to the science of chemistry.

The Distinguished Alumni Award from Wooster is presented annually to alumni who have distinguished themselves in one of more of the following area: professional career; service to humanity; and service to Wooster.

Helen M. Free Award recognizes outstanding achievements in the field of public outreach. 

Ohio Women’s Hall of Fame provides public recognition of contributions made to the growth and progress of Ohio and the nation.
The Fisher Award in Analytical Chemistry recognizes outstanding contributions to the field of analytical chemistry.

U.S. Ramsey Fellow is no longer offered.

Alfred P. Sloan Fellow is awarded to scientists and scholars of outstanding promise.

Outstanding Women in the State of Maryland awards women under the age of 40 for their achievements already made in an early career. 

The American Cyanamid Faculty Award  

The Henry Hill Award recognizes distinguished service to professionalism. 


John S. Guggenheim Foundation Fellow is awarded for demonstrating outstanding scholarship.

Charles Lathrop Parsons Award recognizes outstanding public service. 



The American Institute of Chemists advances the chemical sciences by establishing high professional standards of practice and to emphasize the professional, ethical, economic, and social status of its members for the benefit of society as a whole.

Iota Sigma Pi is a national honor society for women in chemistry.

Much of the information for this post came from the book Notable Women in the Physical Sciences: A Biographical Dictionary edited by Benjamin F. Shearer and Barbara S. Shearer. 

Adrienne M Roehrich, Double X Science Chemistry Editor

Historical Chemists


The twitter feed from @DoubleXSci since early December has featured Notable Historical and Modern Women in Science. Nearly 100 women were presented. Those women will be presented in a series here on the blog with the original tweeted links and information as well as with some additional information not able to be presented in 140 characters. Each woman could have multiple pages written on her; however, I have limited each to a paragraph. I hope you look up more on these women. 

The International Year of Chemistry 2011 recently wrapped up, so I’d like to share a little more about some historical women in chemistry.

Miriam the Alchemist By Michael Maier (1566-1622) 
The first historical woman in chemistry is perhaps Miriam the Alchemist, who lived in the 1st or 2nd century C.E. Her writings survived centuries. She has several aliases: Mary, Maria, and Miriam the Prophetess or Jewess. Even though she was an alchemist, which was mostly a mystical field during her time, her inventions and contributions yielded long-lived practical laboratory equipment. Miriam the Alchemist contributed major inventions and improvements to existing technology, as well as the water bath. The water bath is still in use today for many chemical experiments, as was dubbed “bain-marie” in the 14th century.  

Agnes Fay Morgan (1884-1968) was a pioneer in vitamin research. She earned her B.S., M.S., and Ph.D.  from the University of Chicago. She also established Iota Sigma Pi, an honor society for women chemists. Morgan received the Garvan Medal and the Borden Award and was the only one of her family to attend college. Her efforts brought both nutrition and home economics to scientific disciplines. Besides her teaching position and doing research in academia, she also was an accomplished administrator and worked with the government on many occasions. She had many firsts in her research and an enormous number of publications. 

Colloid Chemist Marjorie Jean Young Vold (1913-1991) was a prolific and distinguished scientist. She earned her B.S. and Ph.D. from University of California, Berkeley. Vold balanced academic and industrial chemist careers spanning over five decades. At the age of 45, she was diagnosed with multiple sclerosis but continued her dual chemistry careers despite being confined to a wheelchair. She was the LA Times Woman of the Year and received the Garvan Medal. One month before her death, Vold submitted her final paper, which was published posthumously.

Lucy Weston Pickett (1904-1997) chose a career in chemistry over marriage. She earned her B.A. and M.A. from Mt. Holyoke College and her Ph.D. from the University of Illinois and advanced through her academic career to become department chair. She received the Garvan Medal and two honorary D.Sc. degrees. She was so influential in her career that a fund was established in her name upon her retirement, which she requested be used to bring female speakers to the department. 

Mary Lura Sherrill (1888-1968) was known for synthesis of antimalarial drugs. She earned her B.A. and M.A. from Randolph-Macon College and her Ph.D. from the University of Chicago. Her academic career included becoming the chair of her department. She also received the Garvan Medal. 

Ellen Swallow Richards
Chemist, Ecologist, and Home Economist Ellen Swallow Richards (1842-1911) was one of Vassar College’s first graduates, with an A.B. She earned her B.S. from MIT as its first woman graduate and her M.A. from Vassar College the same year. She had many firsts, including improving the standard of living by applying chemistry to sanitation, opening up science for women, and developing the home economics movement. Richards was also the first woman member of the American Institute of Mining and Metallurgical Engineers and first woman teacher at the MIT department of sanitary chemistry. She was awarded an honorary doctorate from Smith College.

Grace Medes (1886-1967) was a pioneer in metabolism research.  She earned her B.A. and M.A. from the University of Kansas and her Ph.D. from Bryn Mawr. Her academic career progressed until she became a department head and chairman. She earned the Garvan Medal and several Distinguished Service Citations. Dr. Medes was at the forefront of cancer research and named a rare disease, tyrosinosis [PDF]. 

Marguerite Perey (1909-1975) was the first woman to enter the French Academy of Science in 300 years. She earned her Diplôme d’État de chimiste from École d’enseignement technique féminine and her doctorate from Sorbonne. She worked with Marie Curie and discovered the element francium. Perey received the Lavoisier Prize from the Academie des Sciences and the Silver Medal from the Societe Chimique de France. 

Mary Engle Pennington
Bacteriologist and Chemist Mary Engle Pennington (1872-1952) was a food preservation pioneer. Despite completing the requirements for a B.S. degree at the University of Pennsylvania, she was granted only a Certificate of Proficiency. She earned her Ph.D. from the University of Pennsylvania. Dr. Pennington worked with the government although she hid her gender to receive her credentials. Called “ice woman” due to her advances in food preservation and refrigeration, she was known for a warm personality. Pennington was awarded numerous fellowships and was a member of many other professional organizations and honoraries, and received the Notable Service Medal and the Garvan Medal. 

Pauline Beery Mack (1891-1974) was an instructor and publisher and loved chemistry. She earned her B.A. from Missouri State University, M.A. from Columbia University, Ph.D. from Pennsylvania State College, and a D.Sc. from Moravian College for Women, Western College for Women. She began the publication the Chemistry Leaflet which eventually became published by the American Chemical Society. She received the Distinguished Daughters of Pennsylvania Medal, the Garvan Medal, and the Astronauts Silver Snoopy Award. Dr. Mack also maintained a busy life outside of science, including basketball and music. She taught more than 12,000 undergraduates over her 30 years at Penn State. She was adept at securing funding for her research, no small feat for a woman in the 1930s. Mack continued into an administrative career and worked full time until she was 79.

Awards Mentioned:
The Garvan Medal is an award from the American Chemical Society to recognize distinguished service to chemistry by women chemists.

The Borden Award is given in recognition of distinctive research by investigators in the United States and Canada which has emphasized the nutritive significance of milk or any of its components. 

LA Times Woman of the Year began as annual awards ceremony to honor women for individual achievement and was awarded from 1950 to 1976. 

Lavoisier Prize (Lavoisier Medal) is awarded by the SCF to an individual or institution to distinguish the work or activities involving the chemistry honor.

Distinguished Daughters of Pennsylvania are those whose achievements on a national and statewide scale have been so outstanding that they have brought honor and respect to the commonwealth. 

Astronauts Silver Snoopy Award candidates will have made contributions toward enhancing the probability of mission success, or made improvements in design, administrative/technical/production techniques, business systems, flight and/or systems safety or identification and correction or preventive action for errors.

Much of the information for this post came from the book Notable Women in the Physical Sciences: A Biographical Dictionary edited by Benjamin F. Shearer and Barbara S. Shearer. 

Adrienne M Roehrich, Double X Science Chemistry Editor



Historical Chemists Part II

If you have been watching tweets from @DoubleXSci since early December, you’ll have noticed tweets about Notable Historical and Modern Women in Science. Nearly 100 women were presented over twitter. Those women will be presented in a series here on the blog with the original tweeted links and information as well as with some additional information not able to be presented in 140 characters. We hope you look up more on these women. 


Leonora Neuffer Bilger was the 1953 Garvan Medal winner and a big influence at the University of Hawaii
(1893-1975) Dr. Bilger received her PhD in chemistry from the University of Cinncinnati in 1916. She graduated and went straight into a position as head of the chemistry department at Sweet Briar College. A brief stint at the University of Cinncinnati gave her skills that she later used in her position as Chair of the Department of Chemistry at the University of Hawaii to design a new chemistry laboratory facility. Her post as University of Hawaii Department Head began in 1943 and lasted 11 years. Her research was on asymmetric nitrogen compounds, for which she won the Garvan Medal. 

Nutritional Chemist Mary Letitia Caldwell was a role model and mentor over 6 decades
(1890-1972) Born in Bogota, Columbia of missionaries, she arrived in the U.S. to attend high school.  Dr. Caldwell was supported by her family in her pursuit of education and science. Due to gender restrictions, Caldwell attended a women’s college and stayed on there for teaching initially. This gave her the start on what she is known for: being a role model and mentor for other women for six decades. She received her A.B in 1913 from Western College for Women, her master’s degree in 1919 from Columbia, and her PhD in 1921 from Columbia, where she stayed on to teach. She entered the relatively new at the time field of nutritional chemistry, laying the groundwork for those after her. While Caldwell was well-known for the quality of research and diligence in her work, she also maintained a work-life balance, as an avid hiker, doting aunt, and gardener. 

Emma Perry Carr
Photo from Wikimedia Commons

Emma Perry Carr was a pioneer in UV spectroscopy and a beloved teacher

(1880-1972) Emma Perry Carr first attended Mr. Holyoke College then transferred to and received her B.S. from the University of Chicago in 1905. After a short duration as an instructor at Mt. Holyoke, Dr. Carr returned to the University of Chicago to receive her PhD in 1910. She returned to Mt. Holyoke to become a full professor and head of the department by the age of 33, a post she held for 33 years. Dr. Carr was also a devoted aunt,a fashionable dresser, and a talented storyteller. She had a relationship with Mary Sherrill, another professor at Mt. Holyoke, whom she shared a residence with for 26 years. Emma Perry Carr was the first recipient of the Garvan Medal.

Marie Sklodowska Curie
Photo from Wikimedia Commons

Physicist & Chemist Marie Sklodowska Curie was the first twice Nobel Prize laureate.  

(1867-1934) Much has been written about Marie Curie. She is, perhaps, the first historical figure to come to mind when a person says “Notable Woman in Science.” She is the first person to have been a twice Nobel Laureate. Marya Sklodowska was born in Poland, and lived through the loss of her eldest sister and mother by age 11. After graduating first her in class from high school, she attended a secret university because Polish universities could not admit women. She wished to go to Paris to study, so she worked and saved her money to do so. She was the first women to receive her Licence es Sciences Physiques from the Sorbonne in 1893, graduating first in her class again. She received her Licence es Sciences Mathematiques in 1894 from the same institution. In 1903, she attained her PhD from the University of Parish, the same year she was awarded the Nobel Prize in Physics. Difficulties continued in her personal life, such as the death of her husband in 1906, her own ill health due to radiation poisoning, and her constant fight for her place in her work. She broke so many barriers, being the first woman in so many circumstances. 

(1909-1997) Mary Feiser was encouraged by her parents to excel academically. She attended Bryn Mawr and received her B.S. in chemistry in 1930. She then attended Radcliffe college and worked on her master’s thesis in the lab of Louis F. Feiser at Harvard. She received her A.M. in 1931 and married in 1932. She opted to continue to work in her husband’s lab instead of pursue a PhD because of the funding and Harvard facilities. With her help, 15 papers and 17 books were published by Feiser. However, Harvard never granted her a salary nor official title for 29 years. Even at 85 years of age, Mary Feiser continued to write and publish organic chemistry books, which were well received.

(1876-1950) Dorothy Hahn received her B.A. in chemistry from Bryn Mawr and went to work at Mt. Holyoke College under the auspices of Emma Perry Carr. Together, the two women were a force producing many women chemists. While Dr. Carr ran the chemistry department, it is said Dr. Hahn ran the organic chemistry department. Dr. Hahn pursued and recieved her Ph.D. from Yale University in 1916 due to a fellowship from the AAUW (American Association of University Women). Hahn also preceeded well-known scientists Gilbert Lewis and Irving Langmuir on a theory of valence electrons. Professor Hahn was a huge influence on organic chemistry, teaching, and women in chemistry. 

Allene Rosalind Jeanes was a pioneering researcher with several patents.
(1906-1995) Allene Rosaland Jeanes was born and raised in Texas. She received her A.B with highest honors from Baylor University in 1928. She graduated with her M.A. from the University of California – Berkeley in 1929. She taught for awhile in a few different colleges, then decided to return to graduate school. She attained her PhD from the University of Illinois in 1938. While she wanted to go into pharmaceutical research, opportunities were limited. She took a position at the National Institute of Health. Her research took her through several government positions and had applications in the food industry. She was honored with many awards, including the Garvan Medal and Federal Women’s Award from the U.S. Civil Service Commission.

Nuclear Chemist Ellen Gleditsch was virtually unknown despite her accomplishments.
(1879-1968) The story of Ellen Gleditsch is not well known in her native Norway nor abroad, and signifies how difficult it was for women to be recognized for their work. She received her degree in pharmacology in 1902. She worked with Marie Curie for 5 years, and received her Licencee es Sciences from the Sorbonne in 1912. She went to work at Yale University despite the animosity toward her from the men at the U.S. institutions of Yale and Harvard and received her D.Sc. form Smith College in 1914. In 1929, Oslo University became embroiled in controversy over the decision to advance Ellen Gleditsch to the position of professional chair, and it took a letter from Marie Curie to help quell the public outrage. During her time in Oslo, she also provided a home for scientists fleeing Nazi Germany. She continued to be an advocate and mentor for women in the sciences until her death at age 88.

(1912-1998) Born in Missouri, Anna Jane Harrison was raised on a farm and her childhood science education tended to be “go out and find caterpillars.” She learned about Caterpillar tractors from her father for that assignment. Her high school science teachers inspired her interest in science, so she went to the University of Missouri to earn a B.A. in chemistry in 1933, a B.S. in education in 1935, a M.A. in chemistry in 1937, and a Ph.D. in physical chemistry in 1940. She was the first woman to earn a PhD at the institution. After meeting Lucy Picket and Emma Carr at a meeting of the American Chemical Society (ACS), she went on to work at Mt. Holyoke College, carrying on the traditions established there by Emma Carr and Dorothy Hahn. She also has several more “firsts” including being the first woman to chair the Division of Chemical Education of the ACS and the first woman elected president of the ACS in the 102 year history of the organization up to then. She was honored with the honorary degree of D.Sc. from ten instutitions. She enjoyed traveling and once stated, “What I really like is to go places one isn’t supposed to go.”

Mentioned Awards
The Garvan Medal is an award from the American Chemical Society to recognize distinguished service to chemistry by women chemists.
Nobel Prize: From the site: 
Every year since 1901 the Nobel Prize has been awarded for achievements in physics, chemistry, physiology or medicine, literature and for peace. The Nobel Prize is an international award administered by the Nobel Foundation in Stockholm, Sweden. In 1968, Sveriges Riksbank established The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel, founder of the Nobel Prize. Each prize consists of a medal, personal diploma, and a cash award.

Federal Women’s Award from the U.S. Civil Service Commission was awarded to a woman for a high level of scientific achievement.

Biology Explainer: The big 4 building blocks of life–carbohydrates, fats, proteins, and nucleic acids

The short version
  • The four basic categories of molecules for building life are carbohydrates, lipids, proteins, and nucleic acids.
  • Carbohydrates serve many purposes, from energy to structure to chemical communication, as monomers or polymers.
  • Lipids, which are hydrophobic, also have different purposes, including energy storage, structure, and signaling.
  • Proteins, made of amino acids in up to four structural levels, are involved in just about every process of life.                                                                                                      
  • The nucleic acids DNA and RNA consist of four nucleotide building blocks, and each has different purposes.
The longer version
Life is so diverse and unwieldy, it may surprise you to learn that we can break it down into four basic categories of molecules. Possibly even more implausible is the fact that two of these categories of large molecules themselves break down into a surprisingly small number of building blocks. The proteins that make up all of the living things on this planet and ensure their appropriate structure and smooth function consist of only 20 different kinds of building blocks. Nucleic acids, specifically DNA, are even more basic: only four different kinds of molecules provide the materials to build the countless different genetic codes that translate into all the different walking, swimming, crawling, oozing, and/or photosynthesizing organisms that populate the third rock from the Sun.

                                                  

Big Molecules with Small Building Blocks

The functional groups, assembled into building blocks on backbones of carbon atoms, can be bonded together to yield large molecules that we classify into four basic categories. These molecules, in many different permutations, are the basis for the diversity that we see among living things. They can consist of thousands of atoms, but only a handful of different kinds of atoms form them. It’s like building apartment buildings using a small selection of different materials: bricks, mortar, iron, glass, and wood. Arranged in different ways, these few materials can yield a huge variety of structures.

We encountered functional groups and the SPHONC in Chapter 3. These components form the four categories of molecules of life. These Big Four biological molecules are carbohydrates, lipids, proteins, and nucleic acids. They can have many roles, from giving an organism structure to being involved in one of the millions of processes of living. Let’s meet each category individually and discover the basic roles of each in the structure and function of life.
Carbohydrates

You have met carbohydrates before, whether you know it or not. We refer to them casually as “sugars,” molecules made of carbon, hydrogen, and oxygen. A sugar molecule has a carbon backbone, usually five or six carbons in the ones we’ll discuss here, but it can be as few as three. Sugar molecules can link together in pairs or in chains or branching “trees,” either for structure or energy storage.

When you look on a nutrition label, you’ll see reference to “sugars.” That term includes carbohydrates that provide energy, which we get from breaking the chemical bonds in a sugar called glucose. The “sugars” on a nutrition label also include those that give structure to a plant, which we call fiber. Both are important nutrients for people.

Sugars serve many purposes. They give crunch to the cell walls of a plant or the exoskeleton of a beetle and chemical energy to the marathon runner. When attached to other molecules, like proteins or fats, they aid in communication between cells. But before we get any further into their uses, let’s talk structure.

The sugars we encounter most in basic biology have their five or six carbons linked together in a ring. There’s no need to dive deep into organic chemistry, but there are a couple of essential things to know to interpret the standard representations of these molecules.

Check out the sugars depicted in the figure. The top-left molecule, glucose, has six carbons, which have been numbered. The sugar to its right is the same glucose, with all but one “C” removed. The other five carbons are still there but are inferred using the conventions of organic chemistry: Anywhere there is a corner, there’s a carbon unless otherwise indicated. It might be a good exercise for you to add in a “C” over each corner so that you gain a good understanding of this convention. You should end up adding in five carbon symbols; the sixth is already given because that is conventionally included when it occurs outside of the ring.

On the left is a glucose with all of its carbons indicated. They’re also numbered, which is important to understand now for information that comes later. On the right is the same molecule, glucose, without the carbons indicated (except for the sixth one). Wherever there is a corner, there is a carbon, unless otherwise indicated (as with the oxygen). On the bottom left is ribose, the sugar found in RNA. The sugar on the bottom right is deoxyribose. Note that at carbon 2 (*), the ribose and deoxyribose differ by a single oxygen.

The lower left sugar in the figure is a ribose. In this depiction, the carbons, except the one outside of the ring, have not been drawn in, and they are not numbered. This is the standard way sugars are presented in texts. Can you tell how many carbons there are in this sugar? Count the corners and don’t forget the one that’s already indicated!

If you said “five,” you are right. Ribose is a pentose (pent = five) and happens to be the sugar present in ribonucleic acid, or RNA. Think to yourself what the sugar might be in deoxyribonucleic acid, or DNA. If you thought, deoxyribose, you’d be right.

The fourth sugar given in the figure is a deoxyribose. In organic chemistry, it’s not enough to know that corners indicate carbons. Each carbon also has a specific number, which becomes important in discussions of nucleic acids. Luckily, we get to keep our carbon counting pretty simple in basic biology. To count carbons, you start with the carbon to the right of the non-carbon corner of the molecule. The deoxyribose or ribose always looks to me like a little cupcake with a cherry on top. The “cherry” is an oxygen. To the right of that oxygen, we start counting carbons, so that corner to the right of the “cherry” is the first carbon. Now, keep counting. Here’s a little test: What is hanging down from carbon 2 of the deoxyribose?

If you said a hydrogen (H), you are right! Now, compare the deoxyribose to the ribose. Do you see the difference in what hangs off of the carbon 2 of each sugar? You’ll see that the carbon 2 of ribose has an –OH, rather than an H. The reason the deoxyribose is called that is because the O on the second carbon of the ribose has been removed, leaving a “deoxyed” ribose. This tiny distinction between the sugars used in DNA and RNA is significant enough in biology that we use it to distinguish the two nucleic acids.

In fact, these subtle differences in sugars mean big differences for many biological molecules. Below, you’ll find a couple of ways that apparently small changes in a sugar molecule can mean big changes in what it does. These little changes make the difference between a delicious sugar cookie and the crunchy exoskeleton of a dung beetle.

Sugar and Fuel

A marathon runner keeps fuel on hand in the form of “carbs,” or sugars. These fuels provide the marathoner’s straining body with the energy it needs to keep the muscles pumping. When we take in sugar like this, it often comes in the form of glucose molecules attached together in a polymer called starch. We are especially equipped to start breaking off individual glucose molecules the minute we start chewing on a starch.

Double X Extra: A monomer is a building block (mono = one) and a polymer is a chain of monomers. With a few dozen monomers or building blocks, we get millions of different polymers. That may sound nutty until you think of the infinity of values that can be built using only the numbers 0 through 9 as building blocks or the intricate programming that is done using only a binary code of zeros and ones in different combinations.

Our bodies then can rapidly take the single molecules, or monomers, into cells and crack open the chemical bonds to transform the energy for use. The bonds of a sugar are packed with chemical energy that we capture to build a different kind of energy-containing molecule that our muscles access easily. Most species rely on this process of capturing energy from sugars and transforming it for specific purposes.

Polysaccharides: Fuel and Form

Plants use the Sun’s energy to make their own glucose, and starch is actually a plant’s way of storing up that sugar. Potatoes, for example, are quite good at packing away tons of glucose molecules and are known to dieticians as a “starchy” vegetable. The glucose molecules in starch are packed fairly closely together. A string of sugar molecules bonded together through dehydration synthesis, as they are in starch, is a polymer called a polysaccharide (poly = many; saccharide = sugar). When the monomers of the polysaccharide are released, as when our bodies break them up, the reaction that releases them is called hydrolysis.

Double X Extra: The specific reaction that hooks one monomer to another in a covalent bond is called dehydration synthesis because in making the bond–synthesizing the larger molecule–a molecule of water is removed (dehydration). The reverse is hydrolysis (hydro = water; lysis = breaking), which breaks the covalent bond by the addition of a molecule of water.

Although plants make their own glucose and animals acquire it by eating the plants, animals can also package away the glucose they eat for later use. Animals, including humans, store glucose in a polysaccharide called glycogen, which is more branched than starch. In us, we build this energy reserve primarily in the liver and access it when our glucose levels drop.

Whether starch or glycogen, the glucose molecules that are stored are bonded together so that all of the molecules are oriented the same way. If you view the sixth carbon of the glucose to be a “carbon flag,” you’ll see in the figure that all of the glucose molecules in starch are oriented with their carbon flags on the upper left.

The orientation of monomers of glucose in polysaccharides can make a big difference in the use of the polymer. The glucoses in the molecule on the top are all oriented “up” and form starch. The glucoses in the molecule on the bottom alternate orientation to form cellulose, which is quite different in its function from starch.

Storing up sugars for fuel and using them as fuel isn’t the end of the uses of sugar. In fact, sugars serve as structural molecules in a huge variety of organisms, including fungi, bacteria, plants, and insects.

The primary structural role of a sugar is as a component of the cell wall, giving the organism support against gravity. In plants, the familiar old glucose molecule serves as one building block of the plant cell wall, but with a catch: The molecules are oriented in an alternating up-down fashion. The resulting structural sugar is called cellulose.

That simple difference in orientation means the difference between a polysaccharide as fuel for us and a polysaccharide as structure. Insects take it step further with the polysaccharide that makes up their exoskeleton, or outer shell. Once again, the building block is glucose, arranged as it is in cellulose, in an alternating conformation. But in insects, each glucose has a little extra added on, a chemical group called an N-acetyl group. This addition of a single functional group alters the use of cellulose and turns it into a structural molecule that gives bugs that special crunchy sound when you accidentally…ahem…step on them.

These variations on the simple theme of a basic carbon-ring-as-building-block occur again and again in biological systems. In addition to serving roles in structure and as fuel, sugars also play a role in function. The attachment of subtly different sugar molecules to a protein or a lipid is one way cells communicate chemically with one another in refined, regulated interactions. It’s as though the cells talk with each other using a specialized, sugar-based vocabulary. Typically, cells display these sugary messages to the outside world, making them available to other cells that can recognize the molecular language.

Lipids: The Fatty Trifecta

Starch makes for good, accessible fuel, something that we immediately attack chemically and break up for quick energy. But fats are energy that we are supposed to bank away for a good long time and break out in times of deprivation. Like sugars, fats serve several purposes, including as a dense source of energy and as a universal structural component of cell membranes everywhere.

Fats: the Good, the Bad, the Neutral

Turn again to a nutrition label, and you’ll see a few references to fats, also known as lipids. (Fats are slightly less confusing that sugars in that they have only two names.) The label may break down fats into categories, including trans fats, saturated fats, unsaturated fats, and cholesterol. You may have learned that trans fats are “bad” and that there is good cholesterol and bad cholesterol, but what does it all mean?

Let’s start with what we mean when we say saturated fat. The question is, saturated with what? There is a specific kind of dietary fat call the triglyceride. As its name implies, it has a structural motif in which something is repeated three times. That something is a chain of carbons and hydrogens, hanging off in triplicate from a head made of glycerol, as the figure shows.  Those three carbon-hydrogen chains, or fatty acids, are the “tri” in a triglyceride. Chains like this can be many carbons long.

Double X Extra: We call a fatty acid a fatty acid because it’s got a carboxylic acid attached to a fatty tail. A triglyceride consists of three of these fatty acids attached to a molecule called glycerol. Our dietary fat primarily consists of these triglycerides.

Triglycerides come in several forms. You may recall that carbon can form several different kinds of bonds, including single bonds, as with hydrogen, and double bonds, as with itself. A chain of carbon and hydrogens can have every single available carbon bond taken by a hydrogen in single covalent bond. This scenario of hydrogen saturation yields a saturated fat. The fat is saturated to its fullest with every covalent bond taken by hydrogens single bonded to the carbons.

Saturated fats have predictable characteristics. They lie flat easily and stick to each other, meaning that at room temperature, they form a dense solid. You will realize this if you find a little bit of fat on you to pinch. Does it feel pretty solid? That’s because animal fat is saturated fat. The fat on a steak is also solid at room temperature, and in fact, it takes a pretty high heat to loosen it up enough to become liquid. Animals are not the only organisms that produce saturated fat–avocados and coconuts also are known for their saturated fat content.

The top graphic above depicts a triglyceride with the glycerol, acid, and three hydrocarbon tails. The tails of this saturated fat, with every possible hydrogen space occupied, lie comparatively flat on one another, and this kind of fat is solid at room temperature. The fat on the bottom, however, is unsaturated, with bends or kinks wherever two carbons have double bonded, booting a couple of hydrogens and making this fat unsaturated, or lacking some hydrogens. Because of the space between the bumps, this fat is probably not solid at room temperature, but liquid.

You can probably now guess what an unsaturated fat is–one that has one or more hydrogens missing. Instead of single bonding with hydrogens at every available space, two or more carbons in an unsaturated fat chain will form a double bond with carbon, leaving no space for a hydrogen. Because some carbons in the chain share two pairs of electrons, they physically draw closer to one another than they do in a single bond. This tighter bonding result in a “kink” in the fatty acid chain.

In a fat with these kinks, the three fatty acids don’t lie as densely packed with each other as they do in a saturated fat. The kinks leave spaces between them. Thus, unsaturated fats are less dense than saturated fats and often will be liquid at room temperature. A good example of a liquid unsaturated fat at room temperature is canola oil.

A few decades ago, food scientists discovered that unsaturated fats could be resaturated or hydrogenated to behave more like saturated fats and have a longer shelf life. The process of hydrogenation–adding in hydrogens–yields trans fat. This kind of processed fat is now frowned upon and is being removed from many foods because of its associations with adverse health effects. If you check a food label and it lists among the ingredients “partially hydrogenated” oils, that can mean that the food contains trans fat.

Double X Extra: A triglyceride can have up to three different fatty acids attached to it. Canola oil, for example, consists primarily of oleic acid, linoleic acid, and linolenic acid, all of which are unsaturated fatty acids with 18 carbons in their chains.

Why do we take in fat anyway? Fat is a necessary nutrient for everything from our nervous systems to our circulatory health. It also, under appropriate conditions, is an excellent way to store up densely packaged energy for the times when stores are running low. We really can’t live very well without it.

Phospholipids: An Abundant Fat

You may have heard that oil and water don’t mix, and indeed, it is something you can observe for yourself. Drop a pat of butter–pure saturated fat–into a bowl of water and watch it just sit there. Even if you try mixing it with a spoon, it will just sit there. Now, drop a spoon of salt into the water and stir it a bit. The salt seems to vanish. You’ve just illustrated the difference between a water-fearing (hydrophobic) and a water-loving (hydrophilic) substance.

Generally speaking, compounds that have an unequal sharing of electrons (like ions or anything with a covalent bond between oxygen and hydrogen or nitrogen and hydrogen) will be hydrophilic. The reason is that a charge or an unequal electron sharing gives the molecule polarity that allows it to interact with water through hydrogen bonds. A fat, however, consists largely of hydrogen and carbon in those long chains. Carbon and hydrogen have roughly equivalent electronegativities, and their electron-sharing relationship is relatively nonpolar. Fat, lacking in polarity, doesn’t interact with water. As the butter demonstrated, it just sits there.

There is one exception to that little maxim about fat and water, and that exception is the phospholipid. This lipid has a special structure that makes it just right for the job it does: forming the membranes of cells. A phospholipid consists of a polar phosphate head–P and O don’t share equally–and a couple of nonpolar hydrocarbon tails, as the figure shows. If you look at the figure, you’ll see that one of the two tails has a little kick in it, thanks to a double bond between the two carbons there.

Phospholipids form a double layer and are the major structural components of cell membranes. Their bend, or kick, in one of the hydrocarbon tails helps ensure fluidity of the cell membrane. The molecules are bipolar, with hydrophilic heads for interacting with the internal and external watery environments of the cell and hydrophobic tails that help cell membranes behave as general security guards.

The kick and the bipolar (hydrophobic and hydrophilic) nature of the phospholipid make it the perfect molecule for building a cell membrane. A cell needs a watery outside to survive. It also needs a watery inside to survive. Thus, it must face the inside and outside worlds with something that interacts well with water. But it also must protect itself against unwanted intruders, providing a barrier that keeps unwanted things out and keeps necessary molecules in.

Phospholipids achieve it all. They assemble into a double layer around a cell but orient to allow interaction with the watery external and internal environments. On the layer facing the inside of the cell, the phospholipids orient their polar, hydrophilic heads to the watery inner environment and their tails away from it. On the layer to the outside of the cell, they do the same.
As the figure shows, the result is a double layer of phospholipids with each layer facing a polar, hydrophilic head to the watery environments. The tails of each layer face one another. They form a hydrophobic, fatty moat around a cell that serves as a general gatekeeper, much in the way that your skin does for you. Charged particles cannot simply slip across this fatty moat because they can’t interact with it. And to keep the fat fluid, one tail of each phospholipid has that little kick, giving the cell membrane a fluid, liquidy flow and keeping it from being solid and unforgiving at temperatures in which cells thrive.

Steroids: Here to Pump You Up?

Our final molecule in the lipid fatty trifecta is cholesterol. As you may have heard, there are a few different kinds of cholesterol, some of which we consider to be “good” and some of which is “bad.” The good cholesterol, high-density lipoprotein, or HDL, in part helps us out because it removes the bad cholesterol, low-density lipoprotein or LDL, from our blood. The presence of LDL is associated with inflammation of the lining of the blood vessels, which can lead to a variety of health problems.

But cholesterol has some other reasons for existing. One of its roles is in the maintenance of cell membrane fluidity. Cholesterol is inserted throughout the lipid bilayer and serves as a block to the fatty tails that might otherwise stick together and become a bit too solid.

Cholesterol’s other starring role as a lipid is as the starting molecule for a class of hormones we called steroids or steroid hormones. With a few snips here and additions there, cholesterol can be changed into the steroid hormones progesterone, testosterone, or estrogen. These molecules look quite similar, but they play very different roles in organisms. Testosterone, for example, generally masculinizes vertebrates (animals with backbones), while progesterone and estrogen play a role in regulating the ovulatory cycle.

Double X Extra: A hormone is a blood-borne signaling molecule. It can be lipid based, like testosterone, or short protein, like insulin.

Proteins

As you progress through learning biology, one thing will become more and more clear: Most cells function primarily as protein factories. It may surprise you to learn that proteins, which we often talk about in terms of food intake, are the fundamental molecule of many of life’s processes. Enzymes, for example, form a single broad category of proteins, but there are millions of them, each one governing a small step in the molecular pathways that are required for living.

Levels of Structure

Amino acids are the building blocks of proteins. A few amino acids strung together is called a peptide, while many many peptides linked together form a polypeptide. When many amino acids strung together interact with each other to form a properly folded molecule, we call that molecule a protein.

For a string of amino acids to ultimately fold up into an active protein, they must first be assembled in the correct order. The code for their assembly lies in the DNA, but once that code has been read and the amino acid chain built, we call that simple, unfolded chain the primary structure of the protein.

This chain can consist of hundreds of amino acids that interact all along the sequence. Some amino acids are hydrophobic and some are hydrophilic. In this context, like interacts best with like, so the hydrophobic amino acids will interact with one another, and the hydrophilic amino acids will interact together. As these contacts occur along the string of molecules, different conformations will arise in different parts of the chain. We call these different conformations along the amino acid chain the protein’s secondary structure.

Once those interactions have occurred, the protein can fold into its final, or tertiary structure and be ready to serve as an active participant in cellular processes. To achieve the tertiary structure, the amino acid chain’s secondary interactions must usually be ongoing, and the pH, temperature, and salt balance must be just right to facilitate the folding. This tertiary folding takes place through interactions of the secondary structures along the different parts of the amino acid chain.

The final product is a properly folded protein. If we could see it with the naked eye, it might look a lot like a wadded up string of pearls, but that “wadded up” look is misleading. Protein folding is a carefully regulated process that is determined at its core by the amino acids in the chain: their hydrophobicity and hydrophilicity and how they interact together.

In many instances, however, a complete protein consists of more than one amino acid chain, and the complete protein has two or more interacting strings of amino acids. A good example is hemoglobin in red blood cells. Its job is to grab oxygen and deliver it to the body’s tissues. A complete hemoglobin protein consists of four separate amino acid chains all properly folded into their tertiary structures and interacting as a single unit. In cases like this involving two or more interacting amino acid chains, we say that the final protein has a quaternary structure. Some proteins can consist of as many as a dozen interacting chains, behaving as a single protein unit.

A Plethora of Purposes

What does a protein do? Let us count the ways. Really, that’s almost impossible because proteins do just about everything. Some of them tag things. Some of them destroy things. Some of them protect. Some mark cells as “self.” Some serve as structural materials, while others are highways or motors. They aid in communication, they operate as signaling molecules, they transfer molecules and cut them up, they interact with each other in complex, interrelated pathways to build things up and break things down. They regulate genes and package DNA, and they regulate and package each other.

As described above, proteins are the final folded arrangement of a string of amino acids. One way we obtain these building blocks for the millions of proteins our bodies make is through our diet. You may hear about foods that are high in protein or people eating high-protein diets to build muscle. When we take in those proteins, we can break them apart and use the amino acids that make them up to build proteins of our own.

Nucleic Acids

How does a cell know which proteins to make? It has a code for building them, one that is especially guarded in a cellular vault in our cells called the nucleus. This code is deoxyribonucleic acid, or DNA. The cell makes a copy of this code and send it out to specialized structures that read it and build proteins based on what they read. As with any code, a typo–a mutation–can result in a message that doesn’t make as much sense. When the code gets changed, sometimes, the protein that the cell builds using that code will be changed, too.

Biohazard!The names associated with nucleic acids can be confusing because they all start with nucle-. It may seem obvious or easy now, but a brain freeze on a test could mix you up. You need to fix in your mind that the shorter term (10 letters, four syllables), nucleotide, refers to the smaller molecule, the three-part building block. The longer term (12 characters, including the space, and five syllables), nucleic acid, which is inherent in the names DNA and RNA, designates the big, long molecule.

DNA vs. RNA: A Matter of Structure

DNA and its nucleic acid cousin, ribonucleic acid, or RNA, are both made of the same kinds of building blocks. These building blocks are called nucleotides. Each nucleotide consists of three parts: a sugar (ribose for RNA and deoxyribose for DNA), a phosphate, and a nitrogenous base. In DNA, every nucleotide has identical sugars and phosphates, and in RNA, the sugar and phosphate are also the same for every nucleotide.

So what’s different? The nitrogenous bases. DNA has a set of four to use as its coding alphabet. These are the purines, adenine and guanine, and the pyrimidines, thymine and cytosine. The nucleotides are abbreviated by their initial letters as A, G, T, and C. From variations in the arrangement and number of these four molecules, all of the diversity of life arises. Just four different types of the nucleotide building blocks, and we have you, bacteria, wombats, and blue whales.

RNA is also basic at its core, consisting of only four different nucleotides. In fact, it uses three of the same nitrogenous bases as DNA–A, G, and C–but it substitutes a base called uracil (U) where DNA uses thymine. Uracil is a pyrimidine.

DNA vs. RNA: Function Wars

An interesting thing about the nitrogenous bases of the nucleotides is that they pair with each other, using hydrogen bonds, in a predictable way. An adenine will almost always bond with a thymine in DNA or a uracil in RNA, and cytosine and guanine will almost always bond with each other. This pairing capacity allows the cell to use a sequence of DNA and build either a new DNA sequence, using the old one as a template, or build an RNA sequence to make a copy of the DNA.

These two different uses of A-T/U and C-G base pairing serve two different purposes. DNA is copied into DNA usually when a cell is preparing to divide and needs two complete sets of DNA for the new cells. DNA is copied into RNA when the cell needs to send the code out of the vault so proteins can be built. The DNA stays safely where it belongs.

RNA is really a nucleic acid jack-of-all-trades. It not only serves as the copy of the DNA but also is the main component of the two types of cellular workers that read that copy and build proteins from it. At one point in this process, the three types of RNA come together in protein assembly to make sure the job is done right.


 By Emily Willingham, DXS managing editor 
This material originally appeared in similar form in Emily Willingham’s Complete Idiot’s Guide to College Biology