Which amino acids cannot be produced by the body and must be obtained from food?

• A. essential amino acids
• B. nonessential amino acids
• C. complete protein
• D. glycogen

Answer: (A)

The main concept is essential amino acids: these must come from the diet because the body cannot synthesize them in adequate amounts. Without dietary intake of these nine amino acids (such as histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine), protein synthesis would be limited and bodily functions relying on those amino acids could falter. Nonessential amino acids, on the other hand, can be produced by the body from other compounds, so they don’t have to be consumed. A complete protein is a dietary protein that supplies all essential amino acids in sufficient amounts, while glycogen is a carbohydrate storage molecule, not an amino acid. So the correct idea is the amino acids that must be obtained from food are essential amino acids.