The primary structure of a prot is decided by sequences of amino acids.
The amino acids are sequenced in a linear polypeptide chain which folds as it is being produced.
it is this three - dimensional folded structure that decides the proteins biological activity.
The amino acids in the chain are linked together by a condensation reaction.
This reaction occurs between an amino and carboxylic acid functional group.
There is always a free amino group at the left hand end of the chain and a free carboxylic acid group at the right, these are known respectively as the N - terminus and the C - terminus. These two free functional groups react together and remove one molecule of water. The resulting link is called a peptide bond
