Question

which of the following is true regarding amino acids?
there are 21 amino acids and 11 of them are essential.
there are 20 amino acids and 11 of them are essential.
there are 21 amino acids and 9 of them are essential.
there are 20 amino acids and 9 of them are essential.

Explanation:

Amino acids are the building blocks of proteins. There are 21 protein - forming amino acids. Among them, 9 are essential amino acids. Essential amino acids cannot be synthesized by the human body and must be obtained from the diet.

Answer:

There are 21 amino acids and 9 of them are essential.