An introduction to DNA… via cake

In light of the fact that at least 10% of this blog is cake, it would be criminal of me not to feature the most awesome amalgamation of science and cake that I have ever come across. Made all the more awesome by the fact that it was actually made for me. And that I got to eat it (it tasted amazing).
 Check. This. Out. 

Yes, that is a DNA cake. Yes, it is the coolest thing you have ever seen.
A lot of people, after seeing the DNA cake, asked me whether it was a scientifically accurate cake, so I thought I would take this opportunity to do a mini post introducing one of the most phenomenally beautiful molecular structures that exists. 
Deoxyribonucleic acid (DNA) is the molecule that contains all your genetic information; effectively it holds the blueprint to you. And in my opinion the structure of DNA, the double helix, really is one of the most beautiful things in the universe. It’s just perfect looking, all twisty and twirling (I’m scrabbling for adequate adjectives here), and containing all the genetic information your entire body will ever need. 
The structure of DNA is, as I said, a double helix, which means that it’s made up of two strands twisted around one another. Each strand is formed from a backbone of ribose sugar molecules and phosphate molecules, attached to a series of nucleoside bases. Interactions between these bases are what join the two strands together. An individual unit of DNA, made up of one nucleoside base, one ribose sugar and one phosphate molecule, is called a nucleotide. 
Four different bases are found in DNA, and these are adenine, thymine, cytosine and guanine. Each of them can only bond with one other base. Thymine and adenine can only bond to each other and the same goes for cytosine and guanine. They’re like old married couples, they’re perfectly compatible, they only go together, and they never ever swing. This means that each strand of the double helix is complementary to the other: wherever strand one has a thymine base, strand two will always have an adenine opposite it, and vice versa.
So that’s the basic structure of DNA, two strands bound together. The twisting of the helix comes from hydrogen bonding between the individual nucleotides. Each nucleotide interacts with one 4 positions further along the strand, which results in the double helical structure that we know and love.  
To answer the original question, then… yes the DNA cake is accurate, at least in as far as the base pairing is correct (if red was adenine, yellow was thymine, blue was guanine and green was cytosine, you can see that they’d all be pairing the right base). Obviously the cake doesn’t show the individual sections of the backbone, or any fine molecular details, but then that’s mostly because it’s made of cake, which is not really designed to be used for molecular modelling. So, there you go… a mini introduction to DNA, illustrated with cake. And I bet that’s a sentence that hasn’t been written too many times before.  


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