Question

The abbreviations for amino acids are the first 3 letters of their name. List the 4 exceptions of this rule.

A) Arg, Pro, Ser, Tyr
B) Gly, Asp, Leu, Glu
C) Lys, Met, His, Asn
D) Trp, Cys, Phe, Ile

Answer 1

The four exceptions to the standard three-letter amino acid abbreviations are Trp for tryptophan, Cys for cysteine, Phe for phenylalanine, and Ile for isoleucine.

Step-by-step explanation:

The four exceptions to the rule that the abbreviations for amino acids are the first three letters of their name are Trp for tryptophan, Cys for cysteine, Phe for phenylalanine, and Ile for isoleucine. That is, the correct answer to the list of exceptions is D) Trp, Cys, Phe, Ile. The primary structure of proteins is determined by the sequence of amino acids, which can be described using either the three-letter or one-letter abbreviation for each amino acid. This sequence is always written from the N-terminus to the C-terminus of the protein.