Can our bodies produce all 20 amino acids??

Answer 1

No. In particular, there are "essential amino acids" that humans must have in their diets. Among these are the aromatic amino acids: Phenylalanine, tyrosine, and tryptophan. Only plants and bacteria make these.

Humans can make amino acids from products of carbohydrate metabolism: Glycine from glyoxalic acid; alanine from pyruvic acid; aspartic acid and aspartamine from ketosuccinic acid; glutamic acid and glutamine from oxaloacetic acid.

Answer 2

This is a definite no-no. If we could produce all 20 amino acids, we wouldn't need to be consuming meats or protein-containing vegetables.

Essential amino acids are amino acids that we have to take in from outside because our bodies cannot produce them. Some examples are isoleucine, leucine, lysine, methionine, phenyalanine and arginine.

Non-essential amino acids are so-called because we do not need to take them from outside since our bodies can produce them. Examples are alanine, glycine, proline and serine. However, there are some cases that we need to take in these non-essential amino acids from outside sources, such as when we have a disease that prevents our bodies from synthesizing the amino acid.

Answer 3

No. We cannot produce certain ones. The WHO has guidelines of necessary intake for 10 acids, and recommends also ingesting an unknown quantity of two others.