Final answer:
The body can produce many amino acids but requires diet-based essential amino acids it can't synthesize. The six conditionally essential amino acids are arginine, cysteine, glutamine, tyrosine, glycine, and proline, which the body cannot always synthesize in sufficient amounts.
Step-by-step explanation:
Conditionally Essential Amino Acids
The human body uses 20 amino acids to synthesize proteins, which are divided into categories based on the body's ability to synthesize them. The nine amino acids that cannot be synthesized by the body are known as essential amino acids and must be obtained from the diet. The essential amino acids include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. In contrast, nonessential amino acids are those the body can produce on its own.
In addition to essential and nonessential amino acids, there are six that are considered to be conditionally essential. Conditionally essential amino acids are ones the body typically synthesizes; however, under certain conditions such as illness or stress, the body might not be able to produce adequate amounts, and they must then be obtained from the diet. The six conditionally essential amino acids are arginine, cysteine, glutamine, tyrosine, glycine, and proline.