Question

How many different proteins consisting of $100$ amino acids can be formed from $20$ different amino acids?

• A. ${20}^{100}$
• B. ${100}^{20}$
• C. $2^{20}$
• D. $20\times 100$

Answer 1

The correct option is A ${20}^{100}$

The 20 different amino acids can be arranged in many different combinations to make many different kinds of proteins.

The number of different proteins consisting of n numbers of amino acids is calculated by the formula 20${}^n$.

Hence, total number of proteins = 20${}^{100}$.

Thus, the correct answer is option A.