Molecules that form the basic building blocks of protein; there are 20; 9 are essential (cannot be synthesized by the body) are called what?

Molecules that form the basic building blocks of protein; there are 20; 9 are essential (cannot be synthesized by the body) are called what?

• A. Polypeptide
• B. Genetic code
• C. Amino acids
• D. Codon

Answer: (C)

Proteins are made by linking amino acids together; these molecules are the monomers that form the protein polymers. There are 20 standard amino acids used in human proteins, and nine of them are essential because the body cannot synthesize them and must obtain them from the diet. Essential amino acids include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The other terms refer to different ideas: a polypeptide is a long chain of amino acids; the genetic code is the set of rules that translates DNA into protein sequences; and a codon is a three-nucleotide unit in mRNA that specifies a single amino acid. The question is asking for the molecules that are the building blocks themselves, which are amino acids.

Proteins are made by linking amino acids together; these molecules are the monomers that form the protein polymers. There are 20 standard amino acids used in human proteins, and nine of them are essential because the body cannot synthesize them and must obtain them from the diet. Essential amino acids include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The other terms refer to different ideas: a polypeptide is a long chain of amino acids; the genetic code is the set of rules that translates DNA into protein sequences; and a codon is a three-nucleotide unit in mRNA that specifies a single amino acid. The question is asking for the molecules that are the building blocks themselves, which are amino acids.