Answer:
There are 20 amino acids that make up all proteins in all living things, 12 of those we can make, that other 8 are said to be essential amino acids.
Explanation:
Essential amino acids are those amino acid which is not prepared in the body of living organisms. There are nine essential amino acids i. e. valine, phenylalanine, threonine, histidine, isoleucine, leucine, lysine, tryptophan and methionine. These amino acids are used for building of important substances such as enzymes etc that are necessary for normal growth of body.