(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.
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.
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What about other great gadgets? The DOTKLOK (from $150) is an open-source and hackable digital clock. It also consumes 2W for power! Runners and cyclists who love their gadgets may like the Garmin Forerunner 610 GPS watch ($320). Track your workouts, train like a pro, and analyze all the data this watch feeds to you for the height of fitness.
If DNA is your thing then artwork of your personal DNA is the way to go. Get a kit from DNA 11 and have your personal DNA run on a gel and transfered to a beautiful piece of art (from $199). Perhaps the ultimate in science and technology applied to a single person is having your personal genome sequenced. 23andme ($299) offers a kit to have your DNA genotyped or visit Knome ($4998) for full genome sequencing. There are a number of companies available for personal genotyping and genome sequencing for a range of cost. Another option is to join the Personal Genome Project, and for full disclosure and sharing of your genome with others for scientific purposes, you can have your genome sequenced as a donation to the organization.
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 (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.
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.
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 (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.
Nuclear Physicist Maria Goeppert-Mayer (1906-1972) was the second woman to win the physics Nobel. Her 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.
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 (1912-1997) was a foremost experimental physicist of modern era. She 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 introduction. Her 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.
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.
Deborah is the first Mexican woman to graduate with a physics PhD from Stanford University. She is a physicist, author, and media personality whose initiatives to popularize science have impacted thousands of people around the world. Her passion is to popularize science and motivate young minds to think analytically about the world. This has led her to pioneer learning initiatives in schools and universities in Mexico, Africa, the US and Israel. She is a frequent public speaker and has been recognized by numerous media outlets such as Oprah, CNN, WSJ, TED, DLD, WIRED, Martha Stewart, City of Ideas, Dr. Oz Show, Celebrity Scientist and others. She regularly appears as a science expert on different international TV networks; currently she is the TV host of National Geographic’s “Humanly Impossible” show. And she will appear on the Discovery Channel’s upcoming show ‘You’ve Been Warned.’ You can find Deborah on Twitter, or on her blog, Science With Debbie. You can also find Deborah telling her story for The Story Collider.
DXS: First, can you give me a quick overview of what your scientific background is and your current connection to science?
I grew up in Mexico City in a fairly conservative community, and as a child, I was discouraged from doing and studying science. My parents, family, and peers would all ask, “oh, why don’t you study a more feminine career?” Although I was pretty good in school, I wasn’t exactly a math wizard. I used to say that I loved philosophy and physics – because philosophy was a deep discipline of asking questions about the world. And physics studied the world itself.
It was clear when I was born that my personality waswas quite different to the one of my mom. When I was growing up, my mom was scared because she didn’t know what to do with this little girl that was smart and always asking questions. She is not a naturally curious person, so she kept trying to tame down my curiosity and kept telling me not to tell boys that I was interested in math and science because I would never find a husband. According to her, the life goal for a girl was to find a husband, have kids, and that’s it. Women didn’t have to have a career. (Not that there is anything wrong with not having a career.) My high school teachers and counselors were not so different and encouraged me to go into philosophy or literature, not into math or physics. And my friends in school told me I literally had to be an out of the world genius to be able to study physics.
Given the circumstances, I started studying philosophy in Mexico. There were some classes with logic, and some with a little bit more math, and those were the ones I just devoured! And, at the same time – secretly – I was reading the biographies of scientists. For some bizarre reason, I was hugely attracted to their life stories. I didn’t have any family members, or anyone else for that matter, that had pursued a career in science, so I didn’t have a mentor or a role model. I felt an extreme kinship with Tycho Brahe, who in the late 1500’s was locked in a tower, doing all of these calculations for years, hated by everyone in the town. Go figure! I felt some kinship with these scientists. But I didn’t have the courage nor the means to switch majors. I did confess that I wanted to study another area (physics), but in Mexico one cannot study two majors. So, I studied philosophy for two years.
In the middle of it, I felt way too curious about science and I decided to apply to schools in the US. It was hard at the time because college in Mexico was a lot cheaper than in the states. At the private school where I was attending, my tuition was about $5,000 per year. If I were to come to the US, I would be looking at costs exceeding $35,000 per year. I couldn’t really ask my dad to help me with that price tag so I started to apply everywhere and anywhere that had scholarship opportunities.
I ended up getting a letter from Brandeis
University saying that they would let me take this advanced placement test and write an essay, which, if I did well, would give me a full scholarship. I received a full Wien Scholarship and was to continue studying philosophy in the US. This was probably the nicest thing that has ever happened to me because it opened the path of opportunity.
Brandeis transformed me as a person – I saw females doing science! But, the bravado moment that changed my life was a very general course called Astronomy 101. The teaching assistant, Roopesh, was a very sweet man from India and he saw that my eyes would just light up when I was in that class – I was much more curious than the random student that was just taking it to fulfill some requirement.
At the end of that year, Roopesh and I
were walking around Harvard Square and stopped to sit under a tree. I started to tell him, with tears in my eyes, that I just don’t want to die without trying. What I meant by that is I don’t want to die without trying to do physics. Everyone’s questioning of my decision made me question my actual ability. Everyone telling me ‘no’ hampered my development. I mean, I was good at math, but I definitely didn’t have the same background as all the kids coming in with advanced math and physics courses.
I told Roopesh that I don’t even remember how to solve the equation (a+b)2 – even my algebra was rusty! But, he believed in me and went back to his professor and told him my story. This professor decided to meet with me and ends up telling me about someone who had done this sort of thing in the past. His name was Ed Witten and he went on to become the father of string theory.
He said “Witten had switched from history to physics, and I will let you try too.” With that, he handed me a book on vector calculus called ‘Div, Grad and Curl’ and told me that If I could master it in three months by the end of the summer, they would let me switch my major to physics and also let me bypass the first two years of course work. This would allow me to graduate by the time my scholarship ran out.
I have never in my life experienced the level of scientific passion condensed into such a short amount of time and I am jealous of the person I was that summer. I had so much perseverance and focus. I don’t think I can ever reproduce that intensity again. From the moment I woke up to the moment I went to sleep, and even in my dreams, I only thought about physics. Roopesh, who became my mentor for the summer, taught me.
I always wanted to pay Roopesh for his tutoring, but he would never accept any money. He told me that when he was growing up in the mountains of Darjeeling in India, there was this old man who would climb up to his home and teach him and his sisters English, the musical instrument Tabla, and math. Roopesh’s father always wanted to pay the old man for his tutoring, but the man always declined. The man said that the only way he could ever pay him back was if Roopesh did the same thing with someone else in the world. And by mentoring me, Roopesh fulfilled his payment to the old man.
Out of that, that became a seed for my physics journey and purpose. It is now my life’s mission to do the same for other people in the world – especially women – who feel attracted to science but feel trapped. They for some reason, whether it is social, financial, etc., just can’t find the way toward science. That is the motivation that dictates my actions.
I was able to pull it off and graduated Brandeis Summa Cum Laude with highest honors in physics and philosophy. I went back to Mexico afterwards to figure out what to do next and to spend some time with my family. At the same time, I did a master’s degree in physics at the largest university in Mexico UNAM. My curiosity for physics didn’t diminish and in 1998, I randomly applied to two physics PhD programs in the US. I applied very, very late, but, fortunately, I won a merit-based full scholarship from the Mexican government who provided me with funding, which made it easier for me.
Because I loved biophysics, I did a search on who was doing this line of research. I came across Steven Chu, who is currently the secretary of energy. At the time I was applying, he was at Stanford and was one of the first to manipulate a single strand of DNA with his ‘optical tweezers.’ To me, his story was fascinating! Without really knowing who he was other than what I found on the web, I wrote him an email asking him if I could work in his lab. Had I known who he was – that he had just won the Nobel prize in 1997 – I would have been too intimidated.
I was admitted to Stanford and was invited to work with Dr. Chu, but after two years I decided to switch labs. As expected, it was a very challenging environment and having only studied two years of physics at Brandeis, I wasn’t as prepared as most of the other students. I struggled for the first two years. Everyone worked so extremely hard at Stanford and there I was, struggling to be the best, but, in the beginning, I couldn’t even be average.
Fast forward four years. I had worked my butt off and ended up becoming the first Mexican woman to graduate with a PhD in physics from Stanford. It was the best day of my life – I kept thinking that I was so blessed to have my parents live to see this! It was so moving, I was crying so much and I couldn’t believe what had happened. My friends had flown in from all over the world to be with me. It was amazing.
When people hear what I do, they – especially teenage girls – feel intimidated. But, when they hear the whole story, their tune changes. I tell them that I know what it is like to not understand something. I was not the kind of person where comprehension of my science came naturally. But I did it. And if I can do it, anyone can do it! My story can be inspirational to someone who comes from a background completely lacking in science because they, like me, can reach their goal.
DXS: What ways do you express yourself creatively that may not have a single thing to do with science?
I was always a very curious girl growing up. I had a lot of interests, one of which being theatre. I wanted to be an actress when I was young, but my father didn’t let me pursue that as a career, which was probably a good idea. But, during high school, I went to an after school drama program. I wrote my own plays – three of them – and performed one of them. I was in heaven when I was on stage.
In NY, I have tried to do a little bit of that. Of course, I’ve never done any big roles, but I will be an extra in a film, or if there is a small production being made in Spanish, I will play a part. It doesn’t matter how big the role is – I just love doing something creative and getting into a character.
DXS: What types of productions and/or films have you done?
I don’t think I would come up in the credits as an extra, but I did a movie with Simon Pegg, Kirsten Dunst and Megan Fox in the movie “How to lose Friends and Alienate People.” It was a very, very fun film! In theatre, Jean Genet, who is a French playwright, has a play called The Maids, and I was the madame.
DXS: Do you find that your scientific background informs your creativity, even though what you do may not specifically be scientific?
Debbie talking to the TEDYouth audience about waves.
I have a concept that I call “physics glasses.” And what I mean by that is, for me, physics is not a subject that you just teach in a complex way in a classroom. Rather, physics is something that is related to everyday life. From the moment you wake up, you can just put on your physics glasses. It is a mode of thinking – it is a way where although reality can be very rich and diverse, physics goes very deep and it abstracts commonalities, general principles that apply to many things. To give you an example, I asked the kids in the audience of my TEDYouth talk, “what do the sun, the ocean, and a symphony orchestra have in common?” When just looking at them on the surface, there isn’t much in common. I mean, they are all beautiful things but they are not obviously related. But, to a physicist, they are all waves. You have sound waves, light waves, and water waves and you can interchange many of the concepts in physics to explain all three.
Where most of us see the world with our eyes through light waves, other might see the world differently. Take, for example, my friend Juan, who is blind. He “sees” the world with sound waves – he senses sound as it bounces off the objects around him. Through this, he can bike, play basketball, and do a load of activities using sound as a guide. This is one of my favorite analogies because, really, physics “infects” the way I see the world.
Deborah the Physicist model
To give you a more specific example in the creativity realm, when I got to NY, I felt really un-feminine. When I was studying physics, I felt that if I was even slightly feminine, I wouldn’t be respected. It didn’t help that some of the other women in the physics program at Stanford were more of a “guys girl,” always wearing a baseball cap and t-shirts. Now, since I am Latin, I first showed up wearing a skirt to class, but I quickly learned to dress down. Looking feminine would assure that no one would talk to me in class.
So, when I got to NY, I had an explosion. I wanted to know what it was like to express myself as a woman and my friend suggested that I do some modeling. So I did. It was a brief, lasting about a year. But during that time, my friend, who was a designer from Mexico, asked me to work with her and I wrote and did some videos about the physics of fashion, which also included the physics of high heels video.
Some people could consider fashion to be superficial, but not me. I love fashion and color. But, other scientists generally looked down upon you for liking this sort of thing. This fueled my desire to prove to everyone that there actually is science everywhere, including fashion, and that they shouldn’t be snobs about it. There is complex science in how different materials work, how they interact with the environment and you can prove to the women, like my mother and friends back home who think that science has nothing to do with their everyday lives, that it has EVERYTHING to do with it. So I talked about a Newtonian theory for color – how to pick the right color for you based on how much light the color would reflect on that day, etc.
DXS: Like a more sophisticated version of colors based on your “season?”
I also did pieces on the materials, including some of the newest engineering accomplishments with fabric. For example, I hooked up with a woman and helped her to design a fashionable and very scientific coat. It ended up costing $11,000, but it was made up of nano fibers and it had a patch in it that could detect the temperature and the probability of rain. Based on this probability, it could change permeability of the fabric. It was a very light coat that was comfortable in nice weather, but when it would rain, it would become impermeable to water once it detected a high probability of rain, transforming into a raincoat.
DXS: That’s incredible! I wish it wasn’t $11,000!
DB: Yeah, that’s usually the problems with these technologies. They are often so novel, but one day I’m sure we can figure out how to make things like this scalable.
Science is very much what guides my thinking when I am being creative and I wish I had more time to do creative things while being influenced by a scientific mindset.
DXS: It is so cool that physics has such an incredible overlap with everyday living. Like, when we take a shower, I want to know “how is the water getting pumped from the ground or through pipes and make its way out of the showerhead?” But, as a biochemist, I often find it hard to relate everyday things to biochemistry, but I would like to!
DB: Its funny that you say that. When I try to teach girls that the worst thing they can do is memorize. Critical thinking is so important and they shouldn’t take anything at face value, and they should even question teachers and authoritative figures in their lives. Always ask: what goes into making this? Why is this here? Why is it this way and not another? Constantly ask questions. That s the gift that physics will give you.
DXS: Have you encountered situations in which your expression of yourself outside the bounds of science has led to people viewing you differently–either more positively or more negatively?
Without saying I am a scientist, I can tell you that people have come up to me and told me that before they even hear me speak, they think I am dumb. They are usually surprised that I am smart! I think it is because I am bubbly and friendly and that often makes an impression as being unintelligent. For them it seems that if a woman is intelligent, she is very cold and distant and serious.
I’ve met a lot of physicists, and yes, some of them do tend to be that way, often as a reaction to how others treat them. Or, people would say to me that, because I am Latin, my cultural identity comes across as being warm and the last thing they’d expect me to be into was something as cold as physics. So yeah, I have definitely been judged so many times!
It even happens in my current job on Wall Street, especially with my male peers. When there are off site client meetings, I’m often accompanied by my male sales colleague. Sales people are generally required to know less about the complexities behind our risk models compared to someone on a more research-oriented role, like me and he will bring me along to these sales meetings in case the potential client has more sophisticated questions that go beyond what he can comfortably answer. Many times upon meeting the clients for the first time they think that I am the sales person, there to be the smiling face to sell them something, and that he is the risk modeler. They always direct their mathematical questions to him.
It came to a point where I became so annoyed that I decided to stop caring. Now, my sales colleague goes out for drinks with the clients and I know that I am going to be invisible. So I don’t go anymore. I know that I am always going to struggle to get the full intellectual respect in that industry – it will always be a challenge.
DXS: Have you found that your non-science expression of creativity/activity/etc. has in any way informed your understanding of science or how you may talk about it or present it to others?
Yes, absolutely. For example in Mexico, unlike the US, you absolutely have to do an honors thesis project as an undergradin science. Because I had already studied philosophy for four years, I wanted to do a thesis project in philosophy. But I also wanted to do one in physics. I recall that back in 1997, when you presented a dissertation in front of the physics community, if you had any power point, forget it. You would be immediately be called dumb or not a good physicist. Because, who takes the time to do something fancy! If you had any color in your presentation, forget it!
So, literally, the smartest students in physics were people who didn’t really communicate that well, or didn’t really speak English that well, or just didn’t really make an effort. Their slides were on those overhead projector things with those rolls of plastic sheets, and most of their talks were so confusing and couldn’t be interpreted! But they were respected! It was just assumed that if the formula looked complex, they were probably right.
So what I did was completely different. I infused my talk with my spiciness and color. I did an artwork of liquid crystals, which was my research at Brandeis. Liquid crystals are little cigar-shaped molecules that actually make up the screen of your laptop. If you pass an electric field through them, they all orient themselves and that is how we can use them for displays in our laptops and TVs.
I colored these cigar-shaped molecules with purples and reds and greens, and I tried to explain it at the most basic level. This is because of one my philosophy professors in Mexico, who told me that if you cannot explain what you do to your grandmother or 6 year old niece, you don’t understand what you are doing – I loved it!
And I said to myself that I shouldn’t care what they think. I pretty much expected to not gain a lot of respect from the physics department, but it had the opposite effect! I actually had one of the professors from that department come up to me and tell me that he had never really understood what a liquid crystal looked like or what it really was! He said that “finally I understand [liquid crystals] because of your drawing. Thank you!” It was incredible!
To see the effect on people and from then on, I bounced up in down, I made jokes, I put in creativity. It doesn’t always have a great effect on very serious audiences, but the younger generation is definitely appreciative. When it keeps going well, you gain confidence. And, for me, I even started wearing high heels to the next talk. When someone commented about my attire, I would counter, hey I have a PhD!
DXS: How comfortable are you expressing your femininity and in what ways? How does this expression influence people’s perception of you in, say, a scientifically oriented context?
This question is deep and a little bit of a struggle at the moment. This is because I still have that fear – when I arrived in NY, I did that short stint in modeling and I expressed myself and I would dress very creatively – just like my other girlfriends who were not scientists. But I did feel a little bit of a backlash. By that I mean that I would post a photo of myself on Facebook or something like that. They were pretty pictures, not at all seductive or provocative, and my high school mates, usually male, would write me saying: “I always knew you as a serious person and you have achieved so many things – I am just telling you for your own good that this can really damage your image.” That made me reply with “so you’re telling me that being smart is actually kind of a bummer?” That actually means that I have to dress very differently from what other women wear for the rest of my life?
I remember feeling very upset about all of that. I think that not being taken seriously is still a little bit of a fear of and I think my website has damaged my serious image a little bit. As a scientist, I was very secluded from the outside world. I didn’t have a lot of friends when I moved here, but I did know an amazing and powerful woman who happened to be the CEO of Blip TV. She was insisting that I do videos! So she invited me to her place and showed me how to do video. Being the quick woman that she was, she asked me to make up a name for myself on the spot. When I didn’t answer, she instantly coined “The Science Babe” for me. I was like, sure, what a cool idea!
It was kind of a cute name, but because English is not my first language, I don’t always understand some of the cultural connotations associated with some English words. A few months later, I started to get a few emails from mothers who were upset that I was using my looks. They would say things like “Are you saying that women have to be in the kitchen or wear short skirts to be scientists?” I would answer that no, that was not it at all. I would further explain that I was trying to change the definition of “babe.” If you are smart, if you are empowered, you will be a babe no matter how you look. I am trying to shift what people think of when they think “scientist.”
I don’t feel quite successful with The Science Babe. It seems like there are quite a few people, especially some from the older generation, who say that they’d love to introduce me to fancy science organizations but are worried that the name “the science babe” will make it difficult. Also, I had the BBC wanted to talk to me about doing a TV show in NY, and then they said but there’s so much bad stuff out there about you! And I was like, what do you mean? They answered “All these things with the “science babe” brand…”
It doesn’t happen all the time, but some people are really critical about the science babe theme, citing that its way too feminine. Other female scientists that haven’t gone that route have perhaps discounted my seriousness about science. They assume that what I am doing is not really that important because I do focus on the science everyday life, which is simpler, and it is too much color and too much vivaciousness for our field. I feel like my femininity has decreased over the last few years because I’ve been too nervous about not being taken seriously. It s almost like the balance tipped the other way. I feel like perhaps I’ve feminized things to a fault and now I want to appear more serious. So, I am changing my website to “Science With Debbie” because I really felt the backlash.
It is a struggle to find the balance between being able to express my femininity and presenting myself in a way that people will take me seriously. In a way, I wish I had a little more courage to not care that much about what people have to say about the science babe but, unfortunately, agents have told me that if I don’t go to the “dumbed down version of femininity” I would get better speaking engagements. Being feminine has literally affected my career, and it’s because of other people’s perceptions. I’m never going to be bland, but I will try to change things so I am more serious
DXS: Do you think that the combination of your non-science creativity and scientific-related activity shifts people’s perspectives or ideas about what a scientist or science communicator is? If you’re aware of such an influence, in what way, if any, do you use it to (for example) reach a different corner of your audience or present science in a different sort of way?
The fact that I am approachable and pretty down to earth has allowed me to reach corners of society that more distant and fancy scientists would never even consider. For instance, I am going to a small university to give a talk. Some of my friends ask why I even bother, especially considering that this insitution is not the most renowned university. But, I feel the opposite – it is these corners that need the influence the most! Similarly, when I go to Hispanic high schools, many of the mothers have never seen a scientist. And there I am, a scientist from Mexico, speaking to them and their kids. It is that powerful combination of being a smart and warm female that can be shocking, which is cool.
In line with this, there was an experiment where women were asked to draw a female scientist. Most drew a plain, relatively unattractive woman. Immediately when you break that mold, it has an incredible effect. People say, “Hey! She kind of looks like me and she dresses like me. Maybe I can do science too!” Some girls are afraid that by being smart, boys won’t talk to them. My femininity allows me to be a voice in a field that has tended to isolate themselves from the public, which is bad. Some of my colleagues have become a little snobbish. The fact that I have serious credentials (PhD and 2 postdocs) shows that I had to work like crazy – looks and personality can only go so far. It s hard work that gets you there! Serious science communication has a lot of math and problem solving in order to explain things accurately to the public. So I still feel like I am doing science!
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.