Science Forums 2

[CraigD]

Originally Posted by Pyrotex

Anyway, genes are NOT associated with "tasks" or "processes" or "functions" or even bodily structures. Genes are associated with chemistry. Typically, a gene is associated with specifying an amino acid in a protein or enzyme. When the DNA is scanned within the cell, this process builds a protein or enzyme.

I agree with Pyro’s general statement that individual genes “are associated with chemistry”, not much more complex biological functions. However, that a gene specifies a single amino acid is incorrect.

The DNA/RNA structure that codes for a single amino acid is the codon, and consists of exactly 3 base pairs. There are exactly 64 codons, some of which code for the same amino acid, and 3 codons that don’t code for an amino acid, but rather signal the transcription “factory” involved in expressing proteins to stop.

By modern microbiological definition, a gene specifies an entire protein, which may consist of hundreds of amino acid subunits. In addition to the coding region of a gene – its exons – eukaryotic genes contain non-coding segments – introns – and other regions that don’t encode proteins, but rather aid transcription factors in locating the gene, and are generally considered part of the gene.