Which statement about essential amino acids is correct according to the material?

Which statement about essential amino acids is correct according to the material?

• A. They total 8
• B. They total 10
• C. They total 11
• D. They total 9

Answer: (D)

Essential amino acids must come from the diet because the body cannot synthesize them. For healthy adults, there are nine: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. So the statement that they total nine is correct. Numbers like eight, ten, or eleven would misstate the standard adult list, though some sources discuss additional amino acids as conditionally essential for certain populations or circumstances.

Essential amino acids must come from the diet because the body cannot synthesize them. For healthy adults, there are nine: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. So the statement that they total nine is correct. Numbers like eight, ten, or eleven would misstate the standard adult list, though some sources discuss additional amino acids as conditionally essential for certain populations or circumstances.