Human DNA Genes and Computer's Hard Drive

     Currently it's impossible to accurately estimate the information contained in a cell, because scientists have not yet determined all the different kinds of information present. However the simplest possible living thing is estimated to require 150 DNA genes. If each gene contained the blueprint of a protein 100 amino acids long, the DNA would have to code for 15,000 amino acids.

     An estimate of the information required for each amino acid in a functional protein in 0.84 bits per amino acid. These bits are the same as those used to measure the amount of information stored on a computer's hard drive. If this estimate were correct (it's probably far to low), the smallest amount of information coding for proteins in an organism would be 12,600 bits-approximately the same amount of information as in this sidebar.

     By comparison, the information needed to encode all proteins in humans would represent about 252 million bits or 12,600 typewritten pages. And this is only about 3 percent of the three billion nucleotide "letters" in the human genome. The function of the remaining 97 percent of human DNA remains unknown, although the prospect is good that information is encoded in much of it.