0NobodyInParticularBest Answer 11 years ago Typically only one side of each pair of nucleotides is written down using the letters A,T,G, and C. This is often further shortened by writing a series of one-letter abbreviations for the amino acids that the nucleotide sequence codes for.A short lesson on biochem with analogies:Strings of DNA nucleotides called chromosomes are stored in a protected area of each cell. (Imagine reference books in a library. You can leave bookmarks in them, but you're not allowed to permanently mark in them or take them out of the library.)Some stretches of DNA (called introns) are used as "backups" "spacers" "handles" and other important but non-obvious things. (Imagine these as book margins, bindings, and title pages.)Other stretches of DNA (called exons) are transcribed into strings of mRNA when the cell needs something. A series of exons that do one thing are called a gene. (Imagine these as notes that you were interested in and copied out of the book.)The mRNA is moved out of the nucleus, sliced up a bit, and has "handles" attached. (Imagine taking your notes home, labeling and organizing them.)The mRNA is translated into a string of amino acids called a polypeptide. (Imagine reading the notes, gathering the materials needed to build a house, and telling the builders what to do.)Then the polypeptide (and possibly some others) fold up into a certain shape called a protein, either just by its chemistry and the jostling action of water molecules or with the help of chaperone proteins. (Imagine the builders putting up the house.)You can explore the human genome to your heart's content, but I think you'll find the results overwhelming. There are about three billion base pairs in each copy of the human genome. (And most of your cells have two similar but non-identical copies.) Wikipedia has quite a collection of where and on which chromosomes you can find genes responsible for various proteins and diseases. That might be more interesting for you.