Giving girls…and science…their due

Respecting both is key to bringing girls into the sciences.

By Susan E. Matthews

When deciding what college to attend, I wouldn’t even consider an all-girls school, despite my mother’s encouragement. I refused to believe that my life had been even a little bit different because I was a girl — though years later as a woman in science, I’ve rethought that assumption.

I knew that my mom had to do gymnastics while the boys in her elementary PE classes had played basketball. I also knew that in her first job, as a computer scientist for a small company, she had been asked to answer the phones when they were between secretaries because she was the only woman in the office. As far as I was concerned, this sort of discrimination was a thing of the past, not something affecting my life. I felt like I was in the clear.

But we are not quite in the clear. We may value girls more, but there are still gaps. One of those gaps exists in the sciences — itself an area that we do not value nearly enough. While I did go to a co-ed school, studied science, and worked in a biogeochemistry lab, I’m in the minority. In 2009–2010, women represented less than a quarter of all students in secondary or post-secondary education studying STEM (science, technology, engineering, and math) topics nationally. This disparity has led to great debate over the reasons for the discrepancy. In early February, in a piece addressing the validity of recent findings, two researchers wrote in the Guardian that to resolve this issue, we could continue to insist that young women make up the difference themselves, by finding their own mentors and paving their own way. But beyond individual industry, we can change our institutions. As Chris Chambers and Kate Clancy argue:

The broader societal constraints that lead so few girls to consider themselves “science people” by middle school derive not from whether we push them into science, but what we value in girls as a culture Continue reading

LEGO those gender stereotypes

My daughter, patiently waiting to get her own balloon jetpack.
Photo credit: Phil Blake
Why can’t you understand that my daughter wants a damn jetpack?

Last weekend, I took my daughters to a birthday party that featured a magician/balloon artist.  He was really fantastic with the kids, and kept their attention for close to 1 hour (ONE HOUR!!!).  At the end of his magic show, he began to furiously twist and tie balloons into these amazing shapes, promoting energetic and imaginative play.  Of these shapes was his own, very intricate invention: a jetpack.  

When he completed the first jetpack, I watched as the eyes of my five-year-old daughter, who happens to be a very sporty kid, light up with wonder.  She looked at me and smiled, indicating through her facial expression alone that she wanted the same balloon toy.  But, alas, when it was her turn for a balloon, her requests were met with opposition.  Here was the conversation:

Magician: How about a great butterfly balloon?

Daughter: No thanks, I’d like a jetpack please.

Magician: I think you should get a butterfly.

Daughter: I’d prefer a jetpack.

Magician: But you’re a girl.  Girls get butterflies.

Daughter (giving me a desperate look): But I really want a jetpack!

Realizing that my daughter was becoming unnecessarily upset, especially given the fact that there were 3 boys already engaging in play with their totally awesome jetpacks, myself and the hostess mother intervened.  We kindly reiterated my daughter’s requests for a jetpack.  And, so she was given a jetpack.

Later that evening, my daughter asked me why the magician insisted that she get a butterfly balloon when she explicitly asked for a jetpack.  Not wanting to reveal the realities of gender stereotype at that very point in time, I simply stated that sometimes we (a gender neutral “we”) might have to repeat ourselves so that others understand what we want.  Then she asked, “but why are butterflies only for girls?”

I was able to more or less able smooth it over with her, but it was clear to me that a very archaic reality was still in play, and my daughters were about to inherit it.  While I have nothing against typically female role-playing or dolls or princesses, I do not like when they are assumed to be the preferred activities.  I also do not like the idea that some toys, based on years of “market research,” are designed to basically pigeonhole girls into a June Cleaveresque state of being, especially without alternative play options.

The five LEGO Friends 
For instance, LEGO has recently launched a “for-girls-only” campaign, exemplified by the new “Friends” LEGO kit.  Slathered in pink and purple, this kit is designed around a narrative involving five friends and a pretend city named Heartlake.  Like nearly all cities, Heartlake boasts a bakery, a beauty salon, a cafe, and a veterinarian’s office to take care of sick animals.  However, unlike every city, Heartlake lacks things like a hospital, a fire department, a police station, and a local airport (thought they do have a flying club).  In essence, this toy is facilitating pretend play that centers ONLY on domestication, which absolutely limits both experiences and expectations for girls playing with this toy.  In essence, LEGO is assuming that all girls want the butterfly balloon instead of the jetpack.

Some might think, “jeeze, it’s just a toy!” and dismiss my objection to all that the Friends kit encompasses.  And perhaps when the Friends kit is offered in addition to a variety of toy types – gender neutral, masculine, and feminine – it may not have a significant effect on the mindset of its young, impressionable owner.  But what if that’s not the case?

Traditional LEGO bricks: For boys AND girls, goshdarnit!
LEGO has also gotten it wrong when it comes to the assumption that girls are not into the traditional LEGO blocks.  In fact, just last night, my daughter (the very one who wanted a jetpack) saw a commercial for a LEGO City product – I forgot which one – and asked that we put it on her ever expanding Christmas list.  Furthermore, both of my daughters are huge fans of the LEGO produced show on the Cartoon Network, Ninjago: Masters of Spinjitzu, which is based on the traditional LEGO figures and game.  My oldest daughter is arguably very sporty and may be more inclined to like “boy” things, but my younger daughter is chock-full of sugar and spice and yada yada yada.  She prefers to wear dresses, LOVES shoes, and demands to have her nails painted at all times.  And she still gets down with regular LEGOs and monster trucks and basketball and karate (all her own choices).  So why is LEGO shoving pastel bricks down girls’ throats?    

Gender and play

Play is an important part of cognitive development.  When children engage in play, they learn through discovery, become familiar with their own limitations, gain a better understanding of spatial relationships, become introduced to cause and effect, and, most relevant to this discussion, play exposes children to societal and cultural norms, as well as family values.  Placing limits on play can affect how a child sees him or herself in the world, which can impact both career and lifestyle choices.   

Research (and experience) has shown that the toys kids choose are shaped by societal expectations; however, these expectations are often dictated by marketing teams and their assumptions of what they think their customers want to see, perpetuating a toy culture that has changed little since the 1950s.  Furthermore, parents may impose toys that are gender “appropriate,” or even punish play that does not align with traditional gender expectations.  But what toys do kids actually want to play with?

In 2003, researchers at the University of Nebraska conducted a study to, in part, identify the impact that stereotyped toys have on play in young children.  There were 30 children who participated in this study, ranging in age from 18-47 months.  They were observed for 30 minutes in a room full of toys, with each toy defined as being traditionally masculine, feminine, or gender neutral.  Interestingly, when assessing the toy preferences of the children, boys tended to play with toys that were either masculine or gender neutral, whereas girls played with toys that were largely gender neutral.  These findings were consistent with previous studies showing that girls tend to play with toys that are not traditionally gendered (i.e. blocks, crayons, puzzles, bears, etc).  
Cherney, et al, 2003
Why is there a disconnect between the natural tendencies of toy choice among female children and what marketing executives deem as appropriate toys for girls?  While fantasy play based on domestic scenarios does have its place during normal development, restricting children to certain types of gendered toys can promote a stereotypical mindset that extends into adulthood, possibly adding to the gender inequity seen in the workplace.  Furthermore, assigning and marketing toys to a specific gender may also contribute to the gendering of household duties and/or recreational activities (i.e. only boys can play hockey or only girls do laundry).

This is obviously problematic for females, especially given the disproportionately low number of women executives and STEM professionals (just to name a few).  However, a conclusion from this study that I hadn’t even considered is the idea that overly feminized toys are not good for boys. 

How “girls only” is disadvantageous to boys

When looking at “masculine” versus “feminine” play, one would see that there is some non-overlap when it comes to learned skills.  For instance, “masculine” play often translates into being able to build something imaginative (like a spaceship or other cool technology) whereas “feminine” toys tend to encourage fantasy play surrounding taking care of the home (like putting the baby to sleep or ironing clothes). 

Both types of learning experiences are useful in today’s world, especially given that more women enter the work force and there is growing trend to more or less split household duties.  So when a kid is being offered toys that encourage play that has both masculine and feminine qualities, there is enhanced development of a variety of skills that ultimately translate into real, modern world scenarios.

However, the issue lies in the willingness to provide and play with strongly cross-gender-stereotyped toys.  Because of the number of toys having this quality, there is a huge gender divide when it comes to play, and boys are much less likely to cross gender lines, especially when toys are overtly “girly” (see figure above).  This is most often because of parents and caregivers who discourage play with “girl” toys, usually citing things like “they will make fun of you.”  Toys heavily marketed to match the stereotypical likes of girls, such as the Friends LEGO kit, clearly excludes boys from engaging in play that develops domestic skills (in addition to pigeonholing girls into thinking that girls can only do domestic things).   

Just yesterday, I came across an article on CNN discussing this issue, and it contained anecdotes similar to the one I described above.  The author described how a little girl was scoffed for having a Star-Wars thermos as well as how a little boy was told (by another little girl) that he could not have the mermaid doll he wanted.  My arguments thus far have been centered on developing a variety of skills through play, but I’d also like to add that limiting self-expression could be disastrous for the future wellbeing of an individual. 

There is some progress being made with regard to how toys are being presented in stores.  For instance, the same article described the new Toy Kingdom at Harrod’s, which does not conform to the traditionally separated “boy” and “girl” sections.  Instead, it has “worlds,” such as The Big Top(with circus acts and fairies) or Odyssey(with space crafts and gadgets).  This type of organization allows any child, regardless of gender, to engage in play that facilitates imagination and cognition.

Hey Toys’R Us, are you listening?                

 Final thoughts

Please don’t misinterpret this as being anti-pink, anti-princess, or anti-feminine.  I embrace my own femininity with vigor and pride.  I like to wear dresses and makeup and get my hair did.  Give me a pair of Manolo Blahniks and I will wear the shit out of them.  But I will do so while elbow deep in a biochemical analysis of intracellular cholesterol transport.    

My point is that if you are going to make a toy more appealing to girls by painting it pink, don’t forget to include facets that allow girls to be comfortable with their femininity while providing an experience that promotes empowerment and an unlimited imagination.  Furthermore, don’t exclude boys from getting an experience that helps them acquire skills that are applicable (and desirable) in the modern world.  As it stands right now, toys like the Friends LEGO kit does neither of these and I believe that they major fails, both of the Double X and the XY variety.    

For more, check out Feminist Frequency’s takedown of LEGO:

Judith E. Owen Blakemore and Renee E. Centers, Characteristics of Boys’ and Girls’ Toys, Sex Roles, Vol. 53, Nos. 9/10, November 2005 [PDF, paywall]

Gerianne M. Alexander, Ph.D., An Evolutionary Perspective of Sex-Typed Toy Preferences: Pink, Blue, and the Brain, Archives of Sexual Behavior, Vol. 32, No. 1, , pp. 7–14, February 2003 [PDF, paywall]

Isabelle D. Cherney, Lisa Kelly-Vance, Katrina Gill Glover, Amy Ruane, and Brigette Oliver Ryalls, The Effects of Stereotyped Toys and Gender on Play Assessment in Children Aged 18-47 Months, Educational Psychology: An International Journal of Experimental Educational Psychology, 23:1, 95-106, 2003

Carol J. Auster and Claire S. Mansbach, The Gender Marketing of Toys: An Analysis of Color and Type of Toy on the Disney Store Website, Sex Roles, 2012 [abstract link]

Isabelle D. Cherney and  Kamala London, Gender-linked Differences in the Toys, Television Shows, Computer Games, and Outdoor Activities of 5- to 13-year-old Children, Sex Roles, 2006 [PDF]

Isabelle D. Cherney and Bridget Oliver Ryalls, Gender-linked differences in the incidental memory of children and adults, J Exp Child Psychol, 1999 Apr;72(4):305-28 [abstract link]

Don’t worry so much about being the right type of science role model

Role models: How do they look? (Source)
[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 Vision and 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 [1]. Others studies show that the number of female science teachers  at their school seems to have no effect [2].

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 the science 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. [3] The study caught my eye when PhD student Sara 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:

  1. “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)
  2. “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 powerful influences 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.

[1] 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.

[2] 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.

[3] 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

Further Reading

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.

Survival is Gendered, According to Scholastic

[Editor’s note: We were going to write this as a she said/he said sort of thing with Emily Willingham and Matthew Francis, but then Francis got all serious and did an analysis and stuff. So his smart analysis appears first, and Willingham’s (not quite) equally sober chapter-by-chapter evaluation of the “girls” book follows.]

Last week Ryan North, purveyor of the excellent webcomic Dinosaur Comics, stumbled across a pair of books published by Scholastic. The books are titled For Boys Only: How to Survive Anything and For Girls Only: How to Survive Anything, which already should be a tip-off, but the tables of contents really hammer home a message. As North says, “Maybe – MAYBE – How To Pick Perfect Sunglasses is actually in the same class as Surviving When Your Parachute Fails.” However, it’s obvious that boys and girls are not expected to want to survive the same things, and that the very idea of survival is gendered in these books.

Thanks to the outcry, Scholastic has already announced they will discontinue the titles, which is great. However, I wonder why they approved them in the first place, and their announcement shows that they don’t really understand what the big deal is. My friend JeNel, who is a children’s librarian, points out that Scholastic’s displays are always gendered, with a lovely regressive social agenda. So, shall we break it down for Scholastic?

First, anytime you name two books “For Boys Only” and “For Girls Only”, put an alligator on the cover of one and a pink cell phone on the cover of the other, you’re telling your audience of impressionable children that these books aren’t going to be equivalent. It’s almost inevitable that the “boy” book is going to be full of adventure and the “girl” book is going to be full of social stuff, and that’s the case here. “Survival” for boys includes broken legs, tornadoes, and earthquakes (since boys are obviously the only ones who will ever experience those), while “survival” for girls includes frenemies, brothers, and teaching your cat how to sit. (I suppose treating cat scratches and bites is kind of a survival skill.) In other words, “survival” for girls is a set of potentially useful social skills – which I guess boys don’t need to know. I split the contents into five categories, and assigned each chapter to one of the categories. 

Here’s the breakdown:

  1. True survival skills, where the knowledge could save your life or at least help you cope with injuries (forest fires, flash floods, snakebites, etc.). Not all of these are likely to be experienced (such as polar bear attack), but at least they could happen. The score: “boys” 22, “girls” 0.
  2. Survival skills for science fiction or fantasy scenarios, which are fun, but will never happen in real life (ghost attack, vampire attack, dinosaur attack, etc.). The score: “boys”  4, “girls” 3.
  3. Useful skills and advice for daily life or unusual situations (dealing with annoying people, getting over rejection, etc.). Not all of these are of equal um…significance, unless you think picking the right sunglasses is equivalent to coping with bullies, but I didn’t want to break the categories up too much. The score: “boys” 0, “girls” 23.
  4. Skills and advice for sudden stardom or suddenly becoming rich, which are fun to dream about, I suppose. The score: “boys” 0, “girls” 3.
  5. Teaching your cat how to sit. The score: “boys” 0, “girls” 1.

Let’s ignore the hyperbolic titles, since obviously neither book is intended to actually teach you to survive everything. However, the implications are clear: Boys need to know how to survive broken legs and earthquakes, but girls evidently will never experience that sort of thing. (Or perhaps Scholastic is assuming the girls will always have a knowledgeable boy around to help out. That sentence caused me psychological pain to even type.) Similarly, boys won’t ever need help dealing with bullies, frenemies, or learning how to camp. Either that, or (as Greg Gbur suggests) girls already know how to deal with the hard survival stuff, so they don’t need the book.


So, like, talking on a cell phone held in
one hand while engaged in this activity is so
totally NOT a survival technique. 

GIRLS ONLY: How to Survive Anything!  
Table of Contents

  • How to survive a BFF Fight (Boys don’t have friends and fight with them? What is that thing they’re doing when they’re rolling around all over the floor trying to kill each other?)
  • How to Survive Soccer Tryouts (assuming very male David Beckham once had to do this)
  • How to Survive a Breakout (like this?)
  • How to Show You’re Sorry (because being a boy means never having to show you’re sorry)
  • How to Have the Best Sleepover Ever (My sons have sleepovers; just discreetly double-checked their gonads)
  • How to Take the Perfect School Photo (like this guy did?)
  • How to Survive Brothers (My sons have brothers, two each; they could really use some tips on this)
  • Scary Survival Dos and Don’ts (if it’s scary, don’t do it)
  • How to Handle Becoming Rich (Nooo! Not RICH!)
  • How to Keep Stuff Secret (It’s like, so hard, to like, keep your mouth shut, you know?)
  • How to Survive Tests (At first I thought this said “testes,” and I was confused. That said, apparently females do have more test anxiety than males. It’s because we’re too stressed about that perfect school photo).
  • How to Survive Shyness (Have you met my husband? No? That’s because he’s shy)
  • How to Handle Sudden Stardom (Boys and men never suddenly become stars. Ever)
  • More Stardom Survival Tips (because one chapter on stardom just isn’t enough)
  • How to Survive a Camping Trip (Boys never go camping. Or they automatically know how because they have testes. Or something like that)
  • How to Survive a Fashion Disaster (You see, fashion is an equal-opportunity threat, people)
  • How to Teach Your Cat to Sit (a critical skill, no doubt, but one boys need to know, too)
  • How to Turn a No Into a Yes (I just …  no)
  • Top Tips for Speechmaking (because we’ve never, ever seen a boy give a bad speech)
  • How to Survive Embarrassment (gentlemen, clearly no concern of yours, sudden erections during algebra notwithstanding)
  • How to Be a Mind Reader (I see what you’re thinking here. No. Just no)
  • How to Survive a Crush (So for boys, is the corollary “How to Survive a Lust?”, or what?)
  • Seaside Survival (More than half of the US population lives in a coastal county. I guess all the males in that portion are expendable)
  • How to Soothe Sunburn (like this fellow did)
  • How to Pick Perfect Sunglasses (living proof that boys could use some help with this, too)
  • Surviving a Zombie Attack (two of these people are male)
  • How to Spot a Frenemy (Paul, meet John. Mick, meet Keith. Simon, meet Garfunkel. Freud, meet Jung. See? Boys have frenemies, too!)
  • Brilliant Boredom Busters (Am copying these now for my three sons, for whom a houseful of toys, books, art supplies, games, videos, and movies simply isn’t enough)
  • How to Survive Truth or Dare (see “No., Just no” above)
  • How to Beat Bullies (Is this a recommended approach? ‘Cause I need to do some time traveling, if so)
  • How to be an Amazing Babysitter (You can start by not taking a gendered approach to every single facet of existence of the child you’re babysitting)

Why don’t more girls get the HPV vaccine??

Double X Science is pleased to be able to repost, with permission, this important piece courtesy of author Kate Prengaman and her Xylem blog, focused on spreading science and new ideas.

Imagine if there was a vaccine that could prevent cancer. Everyone would want it, right?
Surprisingly, no. There IS a vaccine to prevent cervical cancer, which, according to the CDC, affects about 12,000 women every year. Unlike most cancers, cervical cancer is caused by a sexually transmitted virus, Human Papillomavirus, also known as HPV. The virus can cause abnormal cell growth in the cervix, which can turn cancerous. The vaccine, approved in 2006, works against many common strains of HPV.
The vaccine is recommended for girls ages 11-12, and also provided to women up through their early twenties.  The goal is to protect girls long before they are ever sexually active, so that they never contract HPV in the first place. As of 2011, the vaccine is also recommended for adolescent boys.
Contracting HPV is so common that more than half of all sexually active men and women in the United States will become infected with HPV at some point in their lives. According to a CDC factsheet on the HPV vaccine, “about 20 million Americans are currently affected, and 6 million more are infected every year.” In most people, HPV infections never lead to symptoms but the virus can cause development of cervical cancer and, more rarely, cancers of the vagina and anus, as well as genital warts. Furthermore, men can develop cancer from HPV. The virus is transmitted through skin to skin contact, which reduces the efficacy of condoms at preventing the spread of this disease.

Yet, despite the dangers associated with HPV, only 33.9% of American girls, ages 13-17, reported to the CDC in 2010 that they had been fully vaccinated (3 doses) against HPV.  When I mapped the state by state rates of vaccination, I found a dramatic distribution, from only 19% of girls in Idaho to nearly 60% in South Dakota and Rhode Island.

Map created by Kate Prengaman
Much of the resistance to vaccinating adolescent girls against cancer-causing HPV comes from  many people who are uncomfortable with or resistant to the fact that adolescent girls will grow up and have sex. I expected to see a strong correlation between states with Abstinence-only sex education and low vaccination rates, but the pattern in the map is weaker than I had anticipated. I also considered that the cost of the vaccines might play a role, although if they are not covered by a family’s health insurance, there are federal programs in place to subsidize the cost. There’s also some correlation there, but again, not as strong as you see, for example, when mapping teenage birthrates.
Map created by Kate Prengaman
Clearly, the pink map, lovely as it is, does not provide an answer for why more adolescent girls are not receiving the HPV vaccine. There is an unfortunate anti-vaccination movement in this country, with people choosing not to protect their kids from dangerous diseases because of unfounded fears that vaccines can cause autism, among other things. Last fall, Michelle Bachmann even used a presidential debate to stir up more fears that the HPV vaccines could cause mental disabilities, a enormous error that the medical community quickly tried to correct.
The truth is that these vaccines are safe. The truth is that HPV is really common, and it can cause cancer, and if you ever have sex, you have a good chance of getting it. Why aren’t more parents of adolescents taking the lead on protecting their kids’ future health?  If you have any ideas for other factors that might explain the patterns of vaccination, let me know in the comments and I  will try adding to my map.  Thanks!

About the guest author:

Kate Prengaman is a science writer and outdoor enthusiast currently based in Madison, WI. Formerly a botanist, Kate is pursuing her masters in science journalism at UW, reading and writing as much as possible.  She loves talking to people, telling stories, finding adventures,  geeking out over wildflowers, and eating delicious things. She blogs at Xylem

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

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


Big Molecules with Small Building Blocks

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

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

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.

Nucleic Acids

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

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

DNA vs. RNA: A Matter of Structure

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

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

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

DNA vs. RNA: Function Wars

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

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

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

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