In eukaryotes, the first amino acid in a growing polypeptide chain is always _______ because the only codon for this amino acid is also the _______. This amino acid is not always the first amino acid in a processed protein because of _______.

Question

Quizplus · Accepted Answer

In eukaryotes, the first amino acid in a growing polypeptide chain is always methionine because the only codon for this amino acid is also the start codon (AUG). This amino acid is not always the first amino acid in a processed protein because of proteolysis, which can cleave off the N-terminal methionine. Therefore, the correct answer is A.

In Eukaryotes, the First Amino Acid in a Growing Polypeptide