How many different tripeptides can be made from glycine, alanine, and valine if the tripeptide contains each amino acid only once?
A) 3
B) 6
C) 18
D) 36

Question

Quizplus · Accepted Answer

Since the tripeptide must contain each of the three amino acids exactly once, the number of different tripeptides is simply the number of ways to arrange these three amino acids. This is a permutation problem, and the number of permutations of three items is 3! (3 factorial), which equals 3*2*1 = 6.

How Many Different Tripeptides Can Be Made from Glycine, Alanine