Which of the following statements gives the most fundamental reason why ornithine is unlikely to be found in proteins synthesized in vivo? a. "there is no codon for it in the standard genetic code"b. "it cannot form a peptide bond"c. "it is not available in the diet"d. "it has a net positive charge in aqueous solution".

option A

Explanation:

ornithine is a non-protein and non-essential amino acid it is formed in plant by L-glutamate and in animals it is formed during the urea cycle by the catalyzation of arginine which is an enzyme. In vivo ornithine is not found in protein synthesis because it do not have any codon so it can not endoded by DNA but can be synthesized.

Ornithine is a precursor of glutamic acid, proline amino acid and citrulline amino acid

true is the final answer!