Which pair of statements best describes an essential amino acid?
it is an amino acid that contains peptide bonds. an example is proline.
it is an amino acid that contains nitrogen. an example is aspartic acid.
it is an amino acid that cannot be made by the body. it must be obtained from eating certain foods.
it is an amino acid that can be produced by the body. vitamin supplements maintain healthy levels.

It is an amino acid that cannot be made by the body. It must be obtained from eating certain foods.

It is an amino acid that cannot be made by the body. It must be obtained from eating certain foods.

Explanation:

An essential amino acid is an amino acid that cannot be synthesized by the body so it must be obtained from eating certain foods. There are mainly 20 amino acids. Out of these 20, some of the amino acids can be synthesized by the body by using essential amino acids as precursor so they are non essential amino acids. The examples of some essential amino acids are histidine, lysine, isoleucine, methionine, phenylalanine, threonine, tryptophan etc.

Tyrosine is a non essential amino acid because can be synthesized by using phenylalanine amino acid as precursor.

Other non-essential amino acids are glutamic acid, cysteine, glycine, proline etc.

i think the answer is gold im not entirely sure

substitution is the answer in this case