1. The Genetic Code

2. The DNA that makes up the human genome can be subdivided into information bytes called genes. Each gene encodes a unique protein that performs a specialized function in the cell. The human genome contains more than 25,000 genes.

3. Note that the code for the mRNA codon is complementary to the code for the DNA codon. There will be one more complementary switch back to the original letters on the tRNA codon (sometimes referred to as the anticodon).

4. Cells use the two-step process of transcription and translation to read each gene and produce the string of amino acids that makes up a protein. The basic rules for translating a gene into a protein are laid out in the Universal Genetic Code. Genetic code - The sequence of DNA nucleotides that determines the amino acid sequence of the translated protein. The genetic code is `read' in triplets of bases called codons.

5. The genetic code shows the amino acid to which each of the 64 possible codons corresponds. To decode a codon, start at the middle of the circle and move outward.