The real scandal: science denialism at Susan G. Komen for the Cure®

Double X Science is pleased to be able to repost, with permission, this important piece courtesy of author Christie Aschwanden and the Last Word on Nothing website, focused on the things that science teaches us we still don’t know…but want to find out. 
You’ll notice that the focus of this article is the way that the Komen foundation blames the individual with the disease for having it, relying on what Aschwanden aptly calls “breast cancer’s false narrative.” This “blame the person” tactic seems to be especially common in women’s health, with an emphasis on the way a woman allegedly does the wrong thing or thinks the wrong thoughts or doesn’t work hard enough willing herself well, making her disease her fault, instead of the fault of nature, mutations, cell division gone astray, and the countless other molecular factors that accumulate into what we call “disease.” In the case of breast cancer, it’s not one monolith of disease that the decision to screen will magically stop.
Many thanks to Christie Aschwanden and the Last Word on Nothing for graciously agreeing to this important repost. –The DXS Editors ——————————————–
Is breast cancer threatening your life? This Susan G. Komen for the Cure® ad leaves no doubt about who’s to blame —you are.
Over the last week or so, critics have found many reasons to fault Susan G. Komen for the Cure®. The scrutiny began with the revelation that the group was halting its grants to Planned Parenthood.  The decision seemed like a punitive act that would harm low-income women (the money had funded health services like clinical breast exams), and Komen’s public entry into the culture wars came as a shock to supporters who’d viewed the group as nonpartisan.* Chatter on the intertubes quickly blamed the move on Komen’s new Vice-President of Public Policy, Karen Handel, a failed GOP candidate who ran for governor in Georgia on a platform that called for defunding Planned Parenthood.** Komen’s founder, Ambassador Nancy Brinker, awkwardly attempted to explain the decision, and yesterday, Handel resigned her position. (Whether she’ll receive a golden parachute remains unclear, but former CEO Hala Moddelmog received $277,864 in 2010, despite her resignation at the end of 2009.)
The Planned Parenthood debacle brought renewed attention to other controversies that have hounded Komen in recent years—like its “lawsuits for the cure” program that spent nearly $1 million suing groups like “cupcakes for the cure” and “kites for the cure” over their daring attempts to use the now-trademarked phrase “for the cure.” Critics also pointed to Komen’s relentless marketing of pink ribbon-themed products, including a Komen-branded perfume alleged to contain carcinogens, and pink buckets of fried chicken, a campaign that led one rival breast cancer advocacy group to ask, “what the cluck?”
But these problems are minuscule compared to Komen’s biggest failing—its near outright denial of tumor biology. The pink arrow ads they ran in magazines a few months back provide a prime example. “What’s key to surviving breast cancer? YOU. Get screened now,” the ad says. The unmistakeable takeaway? It’s your fault if you die of cancer. The blurb below the big arrow explains why. “Early detection saves lives. The 5-year survival rate for breast cancer when caught early is 98%. When it’s not? 23%.”
If only it were that simple. As I’ve written previously here, the notion that breast cancer is a uniformly progressive disease that starts small and only grows and spreads if you don’t stop it in time is flat out wrong. I call it breast cancer’s false narrative, and it’s a fairy tale that Komen has relentlessly perpetuated.
It was a mistake that most everyone made in the early days. When mammography was new and breast cancer had not yet become a discussion for the dinner table, it really did seem like all it would take to stop breast cancer was awareness and vigilant screening. The thing about the false narrative is that it makes intuitive sense–a tumor starts as one rogue cell that grows out of control, eventually becoming a palpable tumor that gets bigger and bigger until it escapes its local environment and becomes metastatic, the deadly trait that’s necessary to kill you. And this story has a grain of truth to it—it’s just that it’s far more complicated than that.
Years of research have led scientists to discover that breast tumors are not all alike. Some are fast moving and aggressive, others are never fated to metastasize. The problem is that right now we don’t have a surefire way to predict in advance whether a cancer will spread or how aggressive it might become. (Scientists are working on the problem though.)
Some breast cancers will never become invasive and don’t need treatment. These are the ones most apt to be found on a screening mammogram, and they’re the ones that make people such devoted advocates of mammography.H. Gilbert Welch of the Dartmouth Institute for Health Policy and Clinical Practice, calls this the overdiagnosis paradox. Overdiagnosis is what happens when a mammogram finds an indolent cancer. A healthy person whose life was never threatened by breast cancer is suddenly turned into a cancer survivor. She thinks the mammogram saved her life, and so she becomes an advocate of the test.
Some cancers behave just the opposite of these slow-growing, indolent ones. Researchers now know that some cancers are extremely aggressive from the start. There’s simply no such thing as “early” detection for these cancers. By the time they’re detectable by any of our existing methods, they’ve already metastasized. These are the really awful, most deadly cancers, and screening mammograms*** will not stop them.
Then there are cancers that fall somewhere in between the two extremes. These are the ones most likely to be helped by screening mammography, and they’re the lives that mammography saves. How many? For women age 50 to 70, routine screening mammography decreases mortality by 15 to 20% (numbers are lower for younger women). One thousand women in their 50′s have to be screened for 10 years for a single life to be saved.
So let’s recap. Getting “screened now,” as the Komen ad instructs can lead to three possible outcomes. One, it finds a cancer than never needed finding. You go from being a healthy person to a cancer survivor, and if you got the mammogram because of Komen’s prodding, you probably become a Komen supporter. Perhaps a staunch one, because hey—they saved your life and now you have a happy story to share with other supporters. Another possibility is that the mammogram finds a cancer that’s the really bad kind, but you die anyway. You probably don’t die later than you would have without the mammogram, but it might look that way because of a problem called “lead time bias.” The third possibility is that you find a cancer that’s amenable to treatment and instead of dying like you would without treatment, your life is saved. Here again, you’re grateful to Komen, and in this case, your life truly was saved.
Right now, breast cancer screening sucks. It’s not very effective, and if you measure it solely based on the number of lives saved versus healthy people unnecessarily subjected to cancer treatments, it seems to cause more harm than good. For every life saved, about 10 more lives are unnecessarily turned upside down by a cancer diagnosis that will only harm them. In a study published online in November, Danish researchers concluded that, “Avoiding getting screening mammograms reduces the risk of becoming a breast cancer patient by one-third.”
But it’s not quite that simple. Some people really are helped by mammography screening, and if you’re the one helped, it’s hard to discount that one life. Right now mammography is the best tool we have. Welch, who has spent more time than probably anyone else in America studying this issue, has deemed the decision about whether or not to get breast cancer screening a “close call.”
Reasonable women can decide that for them, the potential benefits outweigh the risks. Other reasonable women will decide that for them, the risks outweigh the potential benefits.
Komen isn’t wrong to encourage women to consider mammography. But they’re dead wrong to imply that “the key to surviving breast cancer” is “you” and the difference between a 98% survival rate and a 23% one is vigilance on the part of the victim. This message flies in the face of basic cancer biology.
Between 2004 to 2009, Komen allocated 47% of it $1.54 billion toward education and screening.  Much of its education messaging promotes the same false narrative as its ads, which means they are not only not furthering the search for a cure, they are harming the cause. By implying that the solution to breast cancer is screening, Komen distracts attention from the real problem, which is that way too many women (and men) are still dying of breast cancer, and screening is not saving them. We still can’t prevent breast cancer, because we don’t know what causes it.
To explain why Komen’s fixation on an unscientific story matters, I want to introduce you to Rachel Cheetham Moro. Moro was a cancer blogger, but she won’t be weighing in on this latest Komen controversy, because she died Monday of metastatic breast cancer. Before she left us, she had plenty to say about the false narrative Komen was peddling. Last October she wrote,
How dare Komen so FALSELY suggest that a screening mammogram is all it takes to avoid metastatic breast cancer? How dare Komen so CRUELLY suggest that “not getting screened for breast cancer in time” would be THE reason and the FAULT of the person with metastatic disease who misses out on all the experiences and joyous events of a long and healthy life that so many others take for granted? How dare you, Komen? How dare you? Continue reading

Think pink? I’d rather raise a stink

Are some of these possible signs of breast cancer present
in a famous work of art? Image: public domain, US gov
by Liza Gross, contributor
[Ed. note: This article was originally posted on KQED QUEST on October 3, 2012. It is reposted here with kind permission.]
Just a generation ago, October belonged to the colors of fall, when “every green thing loves to die in bright colors,” as Henry Ward Beecher said. (Growing up back East, you read a lot of odes to fall foliage in school.) For years after moving to the Bay Area from Pennsylvania, I felt a twinge of melancholy when October rolled around, knowing the once-demure woodlands would let loose in a fleeting blaze of brash reds and orange-tinged yellows without me.
Now, of course, October belongs to all things pink, as high-profile outfits from the NFL to Ace Hardware set aside 31 days to raise awareness and money for Breast Cancer Awareness Month. (National Breast Cancer Awareness Month was launched in 1985 by CancerCare, a nonprofit cancer support group, and cancer-drug maker AstraZeneca.)
But as women’s health advocate Dr. Susan Love says, awareness of the disease isn’t the issue. “When the NFL is wearing pink gloves, I think you can say we’re aware,” she said last year. “But the awareness isn’t enough.”
Even raising money isn’t enough. You have to ask where that money is going.
It’s a message that gets lost in an ocean of pink-ribbon products (from bagels and teddy bears to vodka and wine glasses), even though critics like the San Francisco-based nonprofit Breast Cancer Action have warned about “pinkwashing” for years, urging people to look behind the feel-good messages to see who’s really benefiting from the commercialization of cancer.
Breast Cancer Action’s Think Before You Pink—Raise a Stink! campaign encourages consumers to think critically about pink products and ask four simple questions to find out what proportion of proceeds go to breast cancer programs and whether the products sold are safe. The group has especially targeted cosmetics companies for marketing pink merchandise even as they sell products with toxic ingredients. (For more information, download the group’s 30-page “toolkit”.)
The group also urges companies to be more transparent and has long called out those it believes use a good cause to increase their bottom line.
Like Eureka, which donated a dollar for every vacuum cleaner sold in its “Clean for the Cure” campaign. Or American Express, which donated a penny per transaction in its “Charge for the Cure.” Both companies bowed out of the pink sweepstakes after Breast Cancer Action asked just how breast cancer patients were benefiting from the campaigns in a 2002 ad in the New York Times.


In October 2000, the San Francisco-based advocacy group 

Breast Cancer Action ran a full page ad in the New York Times 
West Coast Edition with text (not shown) inviting readers to 
participate in its ”Stop Cancer Where It Starts” Campaign. 
The campaign criticized breast cancer awareness campaigns 
for pushing early detection and mammograms 
(without acknowledging their limitations) while ignoring prevention. 
(Image: Courtesy Breast Cancer Action)

Others, like KFC with its 2010 “Buckets for the Cure” campaign, climb on the pink bandwagon to peddle decidedly unhealthy products. Stephen Colbert’s take on the “pink bucket dilemma” shows just how ludicrous cause marketing has become. (Forward to 1:13.)

But even when money goes to breast cancer programs and not corporate coffers, is it going to the right place? Love (and several advocacy groups) has said for years that we need to shift our focus from cures to causes—and prevention.
If we can develop a vaccine for cervical cancer, says Love, why not for breast cancer? Early results of a clinical trial show promising results for a vaccine designed to prevent recurrence of one form of breast cancer. (The data were presented at a meeting and have not yet gone through peer review.)
As I wrote in May, Love’s Research Foundation is looking for volunteers in her online Army of Women to identify potential causes in order to eradicate the disease. (Anyone can sign up.)


In the late 1990s, The Breast Cancer Fund, the American Cancer Society, 

and the Susan G. Komen Breast Cancer Foundation invited American 
artists and writers to submit work about their breast cancer experiences. 
The resulting exhibit (and book)—Art.Rage.Us.—opened in 1998 
at San Francisco’s Main Library. At the time, project coordinator and 
Breast Cancer Action Co-founder Susan Claymon said, 
“Art.Rage.Us. presents deeply moving and beautiful expressions 
from women with breast cancer, along with intensely personal 
statements that provide a window into their hearts and minds.” 
Claymon died of breast cancer in 2000. She was 61.

Prevention is also a primary concern for the Athena Breast Health Network, a partnership of the five University of California medical centers that collects personalized data on breast cancer patients to optimize treatment and ultimately figure out how to stop cancer before it starts. The site also includes a comprehensive list of breast cancer risk factors.

Recent research suggests that the biology behind one of the listed risk factors, dense breast tissue, may be more complicated than previously thought. Earlier studies found that women with dense breasts had a higher risk of developing breast cancer. (And this finding led to the“right to know” legislation that Gov. Brown recently signed, requiring doctors to tell women if their mammograms show they have dense breasts.) But a recent study in the Journal of the National Cancer Institute suggests that women with denser breasts are not more likely to die of breast cancer. The greatest risk was found for women who had the fattiest breast tissue, a condition linked to obesity. This suggests that if you have dense breast tissue, you may be more likely to get cancer—but not die of it. Love’s blog explained the significance of the findings:
The recent study on breast density showed us, yet again, that women who are obese when they are diagnosed with breast cancer are more likely to die of breast cancer than women who are not obese. Doctors need to do more than tell women about their breast density or remind them to get a mammogram. They need to be teaching women the importance of exercising, losing weight (if necessary) and eating a well-balanced diet—both before and after a breast cancer diagnosis. Continue reading

Good Deeds, Good Science: Breast Cancer Research and Education



Normal (left) versus cancerous (right) mammography image.
Public domain, from the National Cancer Institute. 


Recently, funding for breast cancer research and clinical detection has been a highly popular topic of discussion.  There was a very large, collective voice angered by the decision of the Susan G. Komen Breast Cancer Foundation to stop contributing to Planned Parenthood.  And this voice was loud enough to make a difference.


If only breast cancer had ears.


On February 6, 2012, the world lost not one, but two amazing women to breast cancer: Susan Niebur, also known as WhyMommy; and Rachel Cheetham Moro of The Cancer Culture Chronicles.  Both women spoke candidly about their individual battle with metastatic breast cancer. Their deliberate determination to beat this thing was always apparent, whether they showed it through humor (see this “Favorite Things” post by Rachel), or through a deeply rooted sense of gratitude, as exemplified by Susan’s “Going HOME!” post.


Unfortunately, Susan and Rachel are not anomalies. They are but two of the approximately 40,000 women (in US alone) projected to lose the battle in 2012. 


Breast cancer affects 1 in 8 women. These odds put someone you know – your wife, mother, sister, girlfriend, aunt, daughter, friend, cousin, neighbor, co-worker – at risk.


In the “Goodbye” post written by Susan Niebur’s husband Curt (WhyDaddy), he made the following request:


In lieu of flowers, please consider furthering Susan’s legacy through a contribution to the Inflammatory Breast Cancer Research Foundation.  Or please choose to make a difference somewhere, anywhere, to anyone.


To help uphold that request, and to honor Susan, Rachel, and the thousands of women and men diagnosed with breast cancer each year, we at Double X Science have compiled a list of breast cancer charities.  If you have the means, please take time to donate. 


What I have learned from Susan Niebur is that there is more than one kind of breast cancer, and lumps are not required.  This foundation is dedicated to researching the mechanisms involved in the development of inflammatory breast cancer (IBC), a rare but extremely aggressive cancer comprising 1-5% of all breast cancer cases in the US.


Located in the Houston area, The Rose is a non-profit organization dedicated to providing women with breast health essentials, such as mammography screening, diagnosis, support, and treatment to any and all women, regardless of ability to pay. 


This brazen organization is dedicated to eradicating breast cancer BY JANUARY 1, 2020.  That’s less than 8 years from now.  Imagine that.  The NBCCF encompasses hundreds of smaller organizations and represents millions of patients, along with their health care professionals, family, friends, etc. 


Contrary to popular belief, breast cancer affects younger women too.  In fact, I have two friends that were diagnosed before the age of 30.  The mission of this organization is to help scientists and physicians better serve young women affected by breast cancer. 


The mission of the National Breast Cancer Foundation is to increase breast cancer awareness and education.  They’ve also partnered with medical centers across the US to provide free mammography services and diagnostic services to underserved women. 


This is a national education and support organization dedicated to help those who are newly diagnosed, in treatment, or are beyond treatment stages.  It also serves as a support network for the friends and family of those affected by breast cancer.  They have a Survivor’s Helpline – (888) 753-LBBC (5222) – run by trained volunteers and sponsor many conferences in the name of breast cancer education.


Breastcancer.org serves to educate those living with breast cancer, providing the most up to date scientific literature so that those affected by breast cancer can make informed decisions on their health and well being.  You can watch a video about how Breastcancer.org has helped those in need.


If you would like to learn more about these organizations, including how they compare to others across the country, you can go to Charity Navigator.

Ask not what science can do for you

Coast Guard Lt. Cmdr. Kimberly Roman, a general physician,
examines a Trinidadian woman at the Couva District Health Facility

My workaday business is scientific editing. I just completed a behemoth job of hundreds of pages, all focused on reporting the findings of clinical trials (meaning trials involving humans instead of other animals) of a drug that keeps people alive. Among those trials was one in which healthy people participated, which is one way that companies who develop therapies test their treatments. It’s important to know what outcomes are in healthy people as well as those who are targets of the therapy.

I read in these papers how the healthy people responded to the therapy–how they underwent needle sticks for blood draws so that researchers could analyze seemingly every last chemical in their blood, how they dealt with side effects minor and greater, including headaches, vomiting, and other distress, and how their participation helped researchers determine the need for a lower dose. As I read about them and the details of their participation, I though, “Wow.” Here are these healthy people entering clinical trials–yes, they do get paid–and their participation helps guide the application of these therapies for people who would die without them. That is some citizen science.

If you’ve ever taken an FDA-approved drug for anything, you’ve benefited from these people–paid or unpaid–who have entered into clinical trials. We’re all beneficiaries of their contributions, their blood draws, urine samples, headaches, gastrointestinal distress, and time away from their families. And when it comes to women, we can contribute to these trials in many, many ways.

Becoming a part of clinical research means being a part of the practice of science. When I think of the importance of women in clinical research, I think about women like Elizabeth Glaser, who established the Elizabeth Glaser Pediatric AIDS foundation before she–and one of her two children–died of AIDS. Part of the foundation’s focus is funding research into AIDS prevention and cure in children. Elizabeth contracted HIV while receiving a blood transfusion during the birth of her daughter, Ariel, and she passed the virus to both her daughter and her son, Jake, who followed. Ariel died in 1988, but Jake is now a healthy adult, still alive in part thanks to his mother’s work to fund research and to people who participate in clinical trials for therapies against HIV/AIDS. 

Today, December 1, is World AIDS Day. The theme for this year’s day is, “Leading with science, uniting for action.” Since the advent of the first-reported cases of HIV in 1981, more than 25 million people have died of AIDS worldwide. In 2008, 2 million people died, in spite of therapies that now save lives. Almost everyone who now lives with HIV lives in low- and middle-income countries and has no access to these effective therapies. There still is no cure for HIV. 

In the United States, about 1 million people have an HIV infection. Of these, women represent about 27% of new infections each year and 25% of those infected. Clinical trials are one critical way that these women–and their children–can have medical interventions they need to remain healthy. It is one way to lead with science, to unite for action.

Not every day is World AIDS Day, but every day, someone, somewhere–a woman, mother, sister, daughter–needs medical interventions. Historically, women have been underrepresented in clinical studies. Mother, scientist, and four-time breast cancer survivor Susan Niebur, now in deep pain from metastatic breast cancer, has called–repeatedly–for more research into fighting metastatic breast cancer. As she notes, no woman survives this cancer. Thirty percent of cases of breast cancer progress to metastatic (spreading) breast cancer, yet only 3% of funding goes to researching it, even as most women diagnosed with it die within three years. Niebur observes that wearing a ribbon does not cure cancer. She writes, “I just want more time.” 

Part of giving women with breast cancer more time is participating in clinical research studies–studies that need both women who have cancer and women who do not–so that research can advance, drugs in the pipeline can move forward in testing. As Niebur has written, we need an Army of Women willing to get into the trenches of research, get needle sticks, give up urine, and possibly vomit occasionally, so that other women–all women–can benefit from clinical research.

If that need on behalf of other XXers isn’t sufficient, keep in mind that participation in trials can also include other benefits. More and more women are finding that participation pays, literally, sometimes in the thousands of dollars. But it’s not just the money–some women have even reported that their participation has led them to better health, given them more time to spend with their children as they make this money in a few days at a time throughout the year. These are not trivial benefits, and the contributions women make when they participate in trials are not trivial either.

Would you like to learn more about clinical trials, how they work, and where you might find one in which you could participate? A place to start is ClinicalTrials.gov, a database of ongoing and past trials in the United States and around the world. After all, in spite of all of those personal benefits for a participant, the most important part for those who suffer and die is that you participate. In this case, you do not ask science what it can do for you. You ask, on behalf of girls and women and everyone everywhere, What can you do for science?

Emily Willingham 

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

Aren’t you curious?


Source: IFLS
By Courtney Williams, DXS contributor
Recently my on-line science pal Emily J. Willingham asked on Facebook,
“You are a consumer of science. As one, what bothers you about how science is offered to you? What questions do you have? How do you consume scientific information? How do you use it?”
She’s going to be blogging on the Forbes network, see her here, and I’m guessing this was the impetus for that particular set of questions.I had much to say in answer to her questions.
One of my biggest pet peeves is that the most sensational headlines are used- even if they are entirely inaccurate scientifically. For example the recent news about small pox and breast cancer. Headlines like, “New smallpox virus could ‘cure’ breast cancer, studies reveal.” How many ways is that wrong?  Well, it’s not smallpox the researchers were using, it’s a vaccinia virus, which is in the same family as the smallpox virus. Big difference. For instance, there wasn’t a global effort to eradicate cowpox- another vaccinia family member. Just because the viruses are related doesn’t mean they are the same thing. Also, what’s with the quotation marks around cure?Maybe because it’s not actually a cure, not even a treatment, just an interesting experiment done in mice- but cure (even in quotes) makes for a better headline. [If you want to learn about the real science behind that crappy headline, here's the original paper- "Vaccinia Virus GLV-1h153 Is Effective in Treating and Preventing Metastatic Triple-Negative Breast Cancer"]
Articles rarely cite their scientific sources- i.e. linking to the actual journal article they are writing about. For instance, the craptastic example above where the ‘journalist’ (how’s that for quotation marks?) not only failed to link to the original article, he didn’t even mention the journal it was published in, when it was published, or any other info (other than the lead author’s name) that would help a reader find the journal article or additional info on it.
As for sources, it’s important to distinguish for the reader between peer reviewed journal articles and mere opinion pieces on blogs. Take for instance the blog post I wrote about here that appeared on the website of Psychology Today. Many news outlets picked it up and touted it as research that showed it was dangerous to let your infant ‘cry it out’ when really it was just a post (poorly researched, lacking citations, and full of unsupported conjecture and opinion) on the blog of a psychologist. A blog post is NOT the same thing as a peer reviewed journal article. Please journalists, know this!
Another gripe, accuracy is sacrificed for the sake of brevity, which completely defeats the purpose of sharing the science. See above yet again about smallpox as a ‘cure’ for breast cancer.
Another problem I have is the way the media handles funding sources for research studies- they always matter, it’s imperative that scientists report any conflicts of interest that funding sources might prove to be. However, they are not always a sign that researchers are ‘in cahoots’ with the companies that fund them. For instance, would you trust RJ Reynolds to fund unbiased research on smoking and cancer? Probably not. Thus, if at the end of a research article you see a company with a known bias and the findings support their assertions, you are right to be skeptical. However, sometimes the funding merely means a company paid for work to be done, regardless of the outcome. For instance, a pharma company that partners with an academic lab on basic science and published the results in a peer reviewed journal. Or, a drug company that funds the clinical trials for it’s drugs. That’s just the way it works- who else would fund the trial if not the manufacturer? If those types of studies are published in peer reviewed journals, they have been vetted to that extent. Further, with clinical trials, the Federal Drug Administration (FDA) oversees all those trials to help ensure they are unbiased and protect the patients involved as well as the public as a whole. The media seems unable to distinguish.
As for how I generally consume science/scientific information? It’s usually as follows- hear about it on the radio or read a lame article via Yahoo News/Strollerderby/The Stir/etc., assume the author is either full of bologna, got the science partly/mostly wrong, had their more level-headed title replaced by an editor, is totally biased, etc., then I track down the original research article, and possibly seek out commentaries on the work from reliable sources (SciAm blogsDouble X Science, fellow scientists, etc.).
What about how I use it? Well, obviously I’m a scientist, so I ‘use’ science/scientific information professionally every single (work) day to try and cure (no quotation marks) and/or treat cancer. In my personal life, science helps me make healthcare decisions for myself and my family, decide which products to buy or to avoid, answer questions about the natural world when my toddler asks, as  material to blog about and use to dispel misconceptions held by myself and others.
However, a lot of the time I don’t necessarily even use the science I consume. Sometimes I just want to know it. I’m curious.
Pretty frequently people ask me, “How do you know that?” or “Why do you even know that?” I’m not sure how to answer. If it’s a medical question, a lot of the times the answer is, “Well, I have that body part and I want to know how it works.” Or, “Well, I’m taking that medicine, so I looked up how it works.” People forget that science is the basis of everything- it’s how everything works or came to be.  While others seem to find it odd that I’m always looking up the science behind was I see/do/hear about, I find it odd that other don’t seem to question enough.
You’re taking that medicine, you’re having that surgery, you’re using that product right now- don’t you wonder how/why it works? Why aren’t you wondering?
Where’s your curiosity? Don’t you just want to know why the sky is blue? How did you came to be? Why are roses red and violets blue?
Aren’t you curious?
The opinions in this article do not necessarily reflect or conflict with those of the DXS editorial team and its contributors.———————————————
Courtney Williams is a scientist, wife, and mother (in no particular order). She works in the oncology department of a biotech company in the burbs of NYC. She blogs about marriage, motherhood, and science at http://mommacommaphd.wordpress.com/.

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

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

                                                  

Big Molecules with Small Building Blocks

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

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

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

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

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

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

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

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

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

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

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

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

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

Sugar and Fuel

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

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

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

Polysaccharides: Fuel and Form

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

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

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

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

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

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

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

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

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

Lipids: The Fatty Trifecta

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

Fats: the Good, the Bad, the Neutral

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

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

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

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

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

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

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

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

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

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

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

Phospholipids: An Abundant Fat

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

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

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

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

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

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

Steroids: Here to Pump You Up?

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

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

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

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

Proteins

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

Levels of Structure

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

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

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

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

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

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

A Plethora of Purposes

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

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

Nucleic Acids

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

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

DNA vs. RNA: A Matter of Structure

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

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

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

DNA vs. RNA: Function Wars

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

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

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


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

Real science vs. fake science: How can you tell them apart?


Phrenology is a famous pseudoscience that involved determining
a person’s personality based on bumps on the skull.

Pseudoscience is the shaky foundation of practices–often medically related–that lack a basis in evidence. It’s “fake” science dressed up, sometimes quite carefully, to look like the real thing. If you’re alive, you’ve encountered it, whether it was the guy at the mall trying to sell you Power Balance bracelets, the shampoo commercial promising you that “amino acids” will make your hair shiny, or the peddlers of “natural remedies” or fad diet plans, who in a classic expansion of a basic tenet of advertising, make you think you have a problem so they can sell you something to solve it. 

Pseudosciences are usually pretty easily identified by their emphasis on confirmation over refutation, on physically impossible claims, and on terms charged with emotion or false “sciencey-ness,” which is kind of like “truthiness” minus Stephen Colbert. Sometimes, what peddlers of pseudoscience say may have a kernel of real truth that makes it seem plausible. But even that kernel is typically at most a half truth, and often, it’s that other half they’re leaving out that makes what they’re selling pointless and ineffectual.

If we could hand out cheat sheets for people of sound mind to use when considering a product, book, therapy, or remedy, the following would constitute the top-10 questions you should always ask yourself–and answer–before shelling out the benjamins for anything, whether it’s anti-aging cream, a diet fad program, books purporting to tell you secrets your doctor won’t, or jewelry items containing magnets:

1. What is the source Continue reading