How many different dipeptides can be made from the 20 common amino acids?

Question

Quizplus · Accepted Answer

A dipeptide consists of two amino acids. Since there are 20 common amino acids and each position in the dipeptide can be occupied by any of the 20 amino acids, the total number of different dipeptides that can be formed is 20 (for the first position) × 20 (for the second position) = 400. This calculation assumes that the order of amino acids matters, which it does in peptides.

How Many Different Dipeptides Can Be Made from the 20