Which characteristic makes nine amino acids “essential”?

all structural proteins are made from them.

they are not found in nature.

the body cannot make them.

all enzymes are made from them.

The right option is; The body cannot make them.

Amino acids are organic compounds that perform many important roles in the body including building of proteins, and production of neurotransmitters and hormones. Based on some factors, amino acids are grouped into two; essential, and nonessential amino acids. The essential amino acids are the amino acids that the body cannot produce on its own, and must be obtained by eating various foods. The nine essential amino acids are; isoleucine, histidine, leucine, phenylalanine, lysine, tryptophan, methionine, threonine, and valine.

digestion

it excretes wastes