“We must believe that we are gifted for something.”
The future scientist and mother as a girl of 16.
Marie (far left) with her sisters and father. How did they breathe in those corsets? We don’t know.
Marie in 1903, the year she won the Nobel prize in physics. She turned 36 that year.
The scientist in her lab.
Marie in 1911, the year she won the Nobel in chemistry and turned 42.
The only woman.
The anniversary of Marie Curie’s birthday was this week. In celebration, yesterday, we posted a link to a BrainPop video about her and how her story inspired a young boy, and tomorrow, we’ll have more about Marie Curie and other women scientists as inspiration. Marie Curie’s daughter, Irene Joliot-Curie, also was awarded a Nobel prize, in chemistry.
Some more links to information about Marie Curie, scientist and mother:
[Today we have a wonderful guest post from Marie-Claire Shanahan, continuing the conversation about what makes someone a good role model in science. This post first appeared at Shanahan’s science education blog, Boundary Vision, and she has graciously agreed to let us share it here, too. Shanahan is an Associate Professor of Science Education and Science Communication at the University of Alberta where she researches social aspects of science such as how and why students decide to pursue science degrees. She teaches courses in science teaching methods, scientific language and sociology of science. Marie-Claire is also a former middle and high school science and math teacher and was thrilled last week when one of her past sixth grade students emailed to ask for advice on becoming a science teacher. She blogs regularly about science education at Boundary Visionand about her love of science and music at The Finch & Pea.] What does it mean to be a good role model? Am I a good role model? Playing around with kids at home or in the middle of a science classroom, adults often ask themselves these questions, especially when it come to girls and science. But despite having asked them many times myself, I don’t think they’re the right questions. Studying how role models influence students shows a process that is much more complicated than it first seems. In some studies, when female students interact with more female professors and peers in science, their own self-concepts in science can be improved . Others studies show that the number of female science teachers at their school seems to have no effect . Finding just the right type of role model is even more challenging. Do role models have to be female? Do they have to be of the same race as the students? There is often an assumption that even images and stories can change students’ minds about who can do science. If so, does it help to show very feminine women with interests in science like thescience cheerleaders? The answer in most of these studies is, almost predictably, yes and no. Diana Betz and Denise Sekaquaptewa’s recent study “My Fair Physicist: Feminine Math and Science role models demotivate young girls” seems to muddy the waters even further, suggesting that overly feminine role models might actually have a negative effect on students.  The study caught my eye when PhD studentSara Callori wrote about it and shared that it made her worry about her own efforts to be a good role model. Betz and Sekaquaptewa worked with two groups of middle school girls. With the first group (144 girls, mostly 11 and 12 years old) they first asked the girls for their three favourite school subjects and categorized any who said science or math as STEM-identified (STEM: Science, Technology, Engineering and Math). All of the girls then read articles about three role models. Some were science/math role models and some were general role models (i.e., described as generally successful students). The researchers mixed things even further so that some of the role models were purposefully feminine (e.g., shown wearing pink and saying they were interested in fashion magazines) and others were supposedly neutral (e.g., shown wearing dark colours and glasses and enjoying reading).* There were feminine and neutral examples for both STEM and non-STEM role models. After the girls read the three articles, the researchers asked them about their future plans to study math and their current perceptions of their abilities and interest in math.** For the most part, the results were as expected. The STEM-identified girls showed more interest in studying math in the future (not really a surprise since they’d already said math and science were their favourite subjects) and the role models didn’t seem to have any effect. Their minds were, for the most part, already made up. What about the non-STEM identified girls, did the role models help them? It’s hard to tell exactly because the researchers didn’t measure the girls’ desire to study math before reading about the role models. It seems though that reading about feminine science role models took away from their desire to study math both in the present and the future. Those who were non-STEM identified and read about feminine STEM role models rated their interest significantly lower than other non-STEM identified girls who read about neutral STEM role models and about non-STEM role models. A little bit surprising was the additional finding that the feminine role models also seemed to lower STEM-identified girls current interest in math (though not their future interest). The authors argue that the issue is unattainability. Other studies have shown that role models can sometimes be intimidating. They can actually turn students off if they seem too successful, such that their career or life paths seem out of reach, or if students can write them off as being much more talented or lucky than themselves. Betz and Sekaquaptewa suggest that the femininity of the role models made them seem doubly successful and therefore even more out of the students’ reach.
The second part of the study was designed to answer this question but is much weaker in design so it’s difficult to say what it adds to the discussion. They used a similar design but with only the STEM role models, feminine and non-feminine (and only 42 students, 20% of whom didn’t receive part of the questionnaire due to an error). The only difference was instead of asking about students interest in studying math they tried to look at the combination of femininity and math success by asking two questions:
“How likely do you think it is that you could be both as successful in math/science AND as feminine or girly as these students by the end of high school?” (p. 5)
“Do being good at math and being girly go together?” (p. 5)
Honestly, it’s at this point that the study loses me. The first question has serious validity issues (and nowhere in the study is the validity of the outcome measures established). First, there are different ways to interpret the question and for students to decide on a rating. A low rating could mean a student doesn’t think they’ll succeed in science even if they really want to. A low rating could also mean that a student has no interest in femininity and rejects the very idea of being successful at both. These are very different things and make the results almost impossible to interpret.
Second these “successes” are likely different in kind. Succeeding in academics is time dependent and it makes sense to ask young students if they aspire to be successful in science. Feminine identity is less future oriented and more likely to be seen as a trait rather a skill that is developed. It probably doesn’t make sense to ask students if they aspire to be more feminine, especially when femininity has been defined as liking fashion magazines and wearing pink.
Question: Dear student, do you aspire to grow up to wear more pink?
Answer (regardless of femininity): Um, that’s a weird question.
With these questions, they found that non-STEM identified girls rated themselves as unlikely to match the dual success of the feminine STEM role models. Because of the problems with the items though, it’s difficult to say what that means. The authors do raise an interesting question about unattainability, though, and I hope they’ll continue to look for ways to explore it further.
So, should graduate students like Sara Callori be worried? Like lots of researchers who care deeply about science, Sara expressed a commendable and strong desire to make a contribution to inspiring young women in physics (a field that continues to have a serious gender imbalance). She writes about her desire to encourage young students and be a good role model:
When I made the decision to go into graduate school for physics, however, my outlook changed. I wanted to be someone who bucked the stereotype: a fashionable, fun, young woman who also is a successful physicist. I thought that if I didn’t look like the stereotypical physicist, I could be someone that was a role model to younger students by demonstrating an alternative to the stereotype of who can be a scientist. …This study also unsettled me on a personal level. I’ve long desired to be a role model to younger students. I enjoy sharing the excitement of physics, especially with those who might be turned away from the subject because of stereotypes or negative perceptions. I always thought that by being outgoing, fun, and yes, feminine would enable me to reach students who see physics as the domain of old white men. These results have me questioning myself, which can only hurt my outreach efforts by making me more self conscious about them. They make me wonder if I have to be disingenuous about who I am in order to avoid being seen as “too feminine” for physics.
To everyone who has felt this way, my strong answer is: NO, please don’t let this dissuade you from outreach efforts. Despite results like this, when studies look at the impact of role models in comparison to other influences, relationships always win over symbols. The role models that make a difference are not the people that kids read about in magazines or that visit their classes for a short period of time. The role models, really mentors, that matter are people in students’ lives: teachers, parents, peers, neighbours, camp leaders, and class volunteers. And for the most part it doesn’t depend on their gender or even their educational success. What matters is how they interact with and support the students. Good role models are there for students, they believe in their abilities and help them explore their own interests.
My advice? Don’t worry about how feminine or masculine you are or if you have the right characteristics to be a role model, just get out there and get to know the kids you want to encourage. Think about what you can do to build their self-confidence in science or to help them find a topic they are passionate about. When it comes to making the most of the interactions you have with science students, there are a few tips for success (and none of them hinge on wearing or not wearing pink):
§ Be supportive and encouraging of students’ interest in science. Take their ideas and aspirations seriously and let them know that you believe in them. This turns out to be by far one of the most powerfulinfluences in people pursuing science. If you do one thing in your interactions with students, make it this.
§Share with students why you love doing science. What are the benefits of being a scientist such as contributing to improving people’s lives or in solving difficult problems? Students often desire careers that meet these characteristics of personal satisfaction but don’t always realize that being a scientist can be like that.
§Don’t hide the fact that there are gender differences in participation in some areas of science (especially physics and engineering). Talk honestly with students about it, being sure to emphasize that differences in ability are NOT the reason for the discrepancies. Talk, for example, about evidence that girls are not given as many opportunities to explore and play with mechanical objects and ask them for their ideas about why some people choose these sciences and others don’t. There are so many ways to encourage and support students in science, don’t waste time worrying about being the perfect role model. If you’re genuinely interested in taking time to connect with students, you are already the right type.
* There are of course immediate questions about how well supported these are as feminine characteristics but I’m willing to allow the researchers that they could probably only choose a few characteristics and had to try to find things that would seem immediately feminine to 11-12 year olds. I still think it’s a shallow treatment of femininity, one that disregards differences in cultural and class definitions of femininity. (And I may or may not still be trying to sort out my feelings about being their gender neutral stereotype, says she wearing grey with large frame glasses and a stack of books beside her).
**The researchers unfortunately did not distinguish between science and math, using them interchangeably despite large differences in gender representation and connections to femininity between biological sciences, physical sciences, math and various branches of engineering.
 Stout, J. G., Dasgupta, N., Hunsinger, M., & McManus, M. A. (2011). STEMing the tide: Using ingroup experts to inoculate women’s self-concept in science, technology, engineering, and mathematics (STEM).Journal of Personality and Social Psychology, 100, 255-270.
 Gilmartin, S., Denson, N., Li, E., Bryant, A., & Aschbacher, P. (2007). Gender ratios in high school science departments: The effect of percent female faculty on multiple dimensions of students’ science identities.Journal of Research in Science Teaching, 44, 980–1009.
 Betz, D., & Sekaquaptewa, D. (2012). My Fair Physicist? Feminine Math and Science Role Models Demotivate Young Girls Social Psychological and Personality Science DOI: 10.1177/1948550612440735
Buck, G. A., Leslie-Pelecky, D., & Kirby, S. K. (2002). Bringing female scientists into the elementary classroom: Confronting the strength of elementary students’ stereotypical images of scientists. Journal of Elementary Science Education, 14(2), 1-9.
Buck, G. A., Plano Clark, V. L., Leslie-Pelecky, D., Lu, Y., & Cerda-Lizarraga, P. (2008). Examining the cognitive processes used by adolescent girls and women scientists in identifying science role models: A feminist approach. Science Education, 92, 2–20.
Cleaves, A. (2005). The formation of science choices in secondary school.International Journal of Science Education, 27, 471–486.
Ratelle, C.F., Larose, S., Guay, F., & Senecal, C. (2005). Perceptions of parental involvement and support as predictors of college students’ persistence in a science curriculum. Journal of Family Psychology, 19, 286–293.
Simpkins, S. D., Davis-Kean, P. E., & Eccles, J. S. (2006). Math and science motivation: A longitudinal examination of the links between choices and beliefs. Developmental Psychology, 42, 70–83.
Stout, J. G., Dasgupta, N., Hunsinger, M., & McManus, M. (2011). STEMing the tide: Using ingroup experts to inoculate women’s self-concept and professional goals in science, technology, engineering, and mathematics (STEM). Journal of Personality and Social Psychology, 100,255–270.
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.
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.
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.
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.
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.
(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.
(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.
(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.
(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.
(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.
(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.”
The Garvan Medalis 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.
[Ed. note: I (Emily) just attended the National Association of Science Writers annual conference in Raleigh, NC, where I moderated a session on managing the information deluge that can overwhelm those of us who deeply engage in social media. During the session, Tinker Ready noted the all-woman makeup of our panel and asked about the role of social media in helping women in science. She also asked me a few questions after the session. Below is a repost of the resulting piece, which first appeared at Nature’s SpotOn Website. SpotOn focuses on how science is communicated and carried out online, something that obviously interests our Double X Science team a great deal. We repost here with permission, and our thanks to the SpotOn folks.]
The tweet read “What makes this panel rare at science conf? #sciwri12deluge”. The attached photos featured four women leading a session at this weekend’s National Association of Science Writers meeting.
Emily Willingham Credit: Tinker Ready
Moderator and science writer Emily Willingham said she and Scientific American blog editor, Bora Zivkovic, planned it that way when they were putting together a Twitter session for the Raleigh, North Carolina meeting.
“We just thought —how often do you get to see that?” Willingham said, with a nod to the panel. “I go to a lot of scientific conferences and you don’t see this that much.”
The topic of the session was how to manage Twitter. But, the panel’s subtext was: women have a prominent place in scientific social networks. And, said Willingham and others, social networks have a role in promoting women in science.
“What you see on Twitter is a kind of de-gendering, in a positive way, of what people have to say,” she said. “You present more with words on Twitter than with anything else. Words and personality are important. “
Panel member Marie-Claire Shanahan, a science communication professor at the University of Alberta, agreed.
“I don’t pay that much attention on Twitter to whether anyone is male or female,” she said “They are often just a Twitter handle.” Gender “is so much not part of the first impression on Twitter.”
Nor is anything below the neck. “Unfortunately,” Willingham said “…That’s useful.”’
“You see people whose heads you recognize and you think, ‘wow, I had no idea what their bodies looks like’,” she said. “By that time, you’ve already fixed who they are in terms of their personality and what you think of them.
Twitter and other social networks also offer a way for women scientists to connect. It allows women who work at home to stay plugged in. Willingham home schools two of her children. She also manages the Double X Science site, which promises to bring “evidence-based science writing to women.”
“In between, I’m watching Twitter go by,” she said. “I work at home, but in this way, I’m connected to humanity. I’m connected to my colleagues, I’m connected to the conversations that are going on about sciences.”
– Tinker Ready
The opinions expressed in this post do not necessarily agree or conflict with those of the DXS editorial team and contributors.
For your serious Sunday consideration, from Double X Science physics editor, Matthew Francis.
The above courtesy of xkcd, a webcomic of romance, sarcasm, math, and language.
If you had to name the top scientists of the 20th century, any reasonable list must include Polish-French scientist Marie Sklodowska Curie. She won the Nobel Prize twice, a feat only matched by three others: once in physics (in 1903) for her work in radioactivity, a term she coined; and once in chemistry (in 1911) for her discovery of the two chemical elements radium and polonium. Her first prize was shared with her husband Pierre, himself an excellent physicist. She went on hiking trips with Einstein, who complained that she was too energetic in her walking style, as he preferred to dawdle. She was also the only female participant in the great Solvay Conference of 1927, which included many of the great innovators in modern physics. The element curium (96 on the periodic table) and several research institutes are named for her. How can you not admire Curie? Let’s face it: she kicks all of our butts.
It’s easy to think of her as one of the Great Woman Scientists, but without a doubt she was a greater scientist than most of us can ever hope to be, male or female. At the same time, anyone thinking they aren’t great because they aren’t a Madame Curie should stop worrying. One side effect of tokenism — letting one or two representatives from non-majority groups stand in for their entire group — is that it truly sets standards far higher than are reasonable. Curie was an outstanding scientist by anyContinue reading →
Welcome to Double X Science. This site exists to bring science to the woman in you, whoever she is, whatever she does. It’s not only for women in science, but also for women into science. If you’re single, married, dating, a mother, an aunt, a niece, a daughter, a sister, transgendered, born XX, or just feeling womanly…I hope that this site has something of science interest for you.
If you have suggestions for links, ideas, or stories for the site, please let me know.
Recommended reading about the importance of women in science and women into science
It’s tempting to cast the role of women in STEM (Science, Technology, Engineering, and Math) as one of struggles and battles because of their sex, rather than as one of contributions because of their minds. But for Women’s History Month and this Diversity in Science Carnival #14, our focus is the role of women in the enterprise of STEM. There’s more to a woman than her sex and her struggles in science–there is, after all, the enormous body of work women have contributed to science.
Our history is ongoing, but we can start with a look back. Thanks to the efforts of the Smithsonian Institution Archives, we can put faces to the names of some of the female STEMmers of history. In a presentation of photographs in an 8 by 9 space, we can see the images of 72 women who contributed to the enterprise of STEM, many of them involved with the Smithsonian in some capacity. As their clothes and the dates on the photos tell us, these women were doing their work in a time when most women didn’t even wear pants.
Some are Big Names–you’ve probably heard of Marie Curie. But others are like many of us, women working in the trenches of science, contributing to the enterprise of STEM in ways big and small. Women like Arlene Frances Fung, whose bio tells us she was born in Trinidad, went to medical school in Ireland, and by 1968 was engaged in chromosome research at a cancer institute in Philadelphia. From Trinidad to cancer research, her story is one of the millions we could tell about women’s historical contributions to science, if only we could find them all. But here there are 72, and we encourage you to click on each image, look at their direct gazes, ponder how their interest in science and knowledge trumped the heavy pressures of social mores, and discover the contributions these 72 women made, each on her own “little two inches wide of ivory.”
For more on historical and current women in science, you can also see Double X Science’s “Notable Women in Science” series, curated by Adrienne Roehrich.
And then there are the women STEMmers of today, who likely are, according to blogger Emma Leedham writing at her blog Pipettes and Paintbrushes, still underpaid. Leedham also mulls here what constitutes a role model for women–does it require being both a woman and a scientist, or one or the other?
Laurel L. James
Laurel L. James, writing at the University of Washington blog for the school’s SACNAS student chapter, answers with her post, “To identify my role as a woman in science: I must first honor my mother, my family and my past.” Her mother was the first “Miss Indian America,” and Laurel is a self-described non-traditional student at the school, where she is a graduate student in forest resources. She traces her journey to science, one that involved role models who were not scientists but who, as she writes, showed her “how to hang onto the things that are important with the expectation of getting something in return all the while, persevering and knowing who you are; while walking with grace and dignity.” I’d hazard that these words describe many a woman who has moved against the currents of her society to contribute something to the sciences.
A great site, Steminist.com, which features the “voices of women in science, tech, engineering, and math,” runs a series of interviews with modern-day STEMmers, including Double X Science’s own Jeanne Garbarino, and Naadiya Moosajee, an engineer and cofounder of South African Women in Engineering. You can follow Naadiya on Twitter here. Steminist is also running their version of March Madness, except that in honor of Women’s History Month, we can choose “Which historical women in STEM rock (our) world.” The 64 historical STEMinists in the tourney are listed here and include Emily Warren Robling (left), who took over completion of the Brooklyn Bridge when her husband’s health prevented his doing so; she is known as the first woman field engineer. Double X Science also has a series about today’s women in science, Double Xpression, which you can find here.
Today, you can find a woman–or many women–in STEM just about anywhere you look, whether it is as a government scientist at NOAA like Melanie Harrison, PhD, or at NASA. It hasn’t always been that way, and it can still be better. But women have always been a presence in STEM. In the 18thand 19th centuries, astronomer Caroline Herschellabored away through the dark hours of just about every night of her adult life, tracking the night sky. Today, women continue these labors, and STEM wouldn’t be what it is today without women like Herschel willing to stay up all night with the skies or spend days on end in the field or lean over a microscope for hours just to add a tiny bit more to what we know about our world and our universe.
For women in science, we’re there–at night, in the lab, in the field–because we love science. But as the non-science role models seem to tell us, we stick to it–and can stick with it–because we had role models in and out of science who showed us that regardless of our goals, our attitudes and willingness to move forward in spite of obstacles are really what drive us to success in STEM careers. Among the links I received for this carnival was one to Science Club for Girls, which is sponsoring a “Letter to My Young Self” roundup for Women’s History Month. The letters I’ve read invariably have that “stick with it” message, but one stood out for me, and I close with a quote from it.
It’s a letter by Chitra Thakur-Mahadik, who earned her PhD in biochemistry and hemoglobinopathy from the University of Mumbai and served as staff scientist a Mumbai children’s hospital for 25 years. She wrote to her younger, “partially sighted” self that, “The future is ahead and it is not bad!” She goes on to say, “Be fearless but be compassionate to yourself and others… be brave, keep your eyes and ears open and face the world happily. What if there are limitations? Work through them with awareness. —Yours, Chitra”
Links and resources for women in STEM, courtesy of D.N. Lee
Stay tuned for the April Diversity in Science Carnival #15: Confronting the Imposter Syndrome. This topic promises to resonate for many groups in science. I’m pretty sure we’ve all felt at least of twinge of imposter syndrome at some point in our education and careers. Your editor for this carnival will be the inimitable Scicurious, who blogs at Scientific American and Scientopia.
UPDATE: Carnival #15 is now available! Go read about imposter syndrome, why it happens, who has it, and what you can do about it.
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.
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.
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].
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.
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.
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.