DNA is represented by an alphabet of the following symbols: 'A', 'C', 'G', and 'T'.

Each symbol represents a nucleotide, which is a fancy name for the particular molecules that happen to make up a large part of DNA.

Shortest intro to biochemistry EVAR:

• twigs are to birds nests as
• nucleotides are to DNA and RNA as
• amino acids are to proteins as
• sugar is to starch as
• oh crap lipids

I'm not going to talk about lipids because they're crazy complex.

So back to nucleotides.

DNA contains four types of them: adenine (A), cytosine (C), guanine (G), and thymine (T).

RNA contains a slightly different set of nucleotides, but we don't care about that for now.