What is a codon? (for my honors biology final tomorrow, ! )

A codon is the 3 nucleotide sequence which codes for an amino acid, stop or start signal in translating a protein.

example:
common mRNA start codon is AUG
(Adenine, Uracil, Guanine)

one of the codons for the amino acid Alanine is : GCU
from general genetic code table for RNA.

codons will be abreviated by 3 nucleotide letters A, G, U, T, C

Uracil is only in RNA codons
there are also DNA codon tables
these tables are a general guide as different organisms may have special codons they utilize.
below is a table of the twenty most common amino acids that make up proteins, below each are the codons generally found to code fore them.

The salt in the sea water dehydrated the sailor because her body could not take in the amount to salt in the sea water