Amino acids not coded by triplet codona) Lysineb) Hydroxyprolinec) Selenocysteined) Pyrrolysinee) Ornithine
be
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bc
ce
Selenocysteine is 21st AA coded by UGA which is normally a stop codon.
Pyrrolysine is 22nd AA coded by UGA which is also a stop codon normally.
Lysine is also an essential amino acid so has to be coded by codon (AAA, AAG).
Hydroxyproline and hydroxylysine are not coded by a codon, i.e. they are not incorporated into protein during translation. Rather, they are formed in protein, by post-translational modification (hydroxylation) of proline and lysine, respectively.
"Ornithine is not an amino acid coded for by DNA, and, in that sense, is not involved in protein synthesis.