The primary structure of a protein refers to the
A) interactions among two or more polypeptides.
B) alpha helix or pleated sheets.
C) side groups of the amino acids.
D) number and sequence of amino acids.
E) DNA nucleotide sequence that coded for it. The primary structure is comprised of the sequence of amino acids that have been joined together through peptide bonding.

Question

Quizplus · Accepted Answer

The primary structure of a protein is determined by the number and sequence of amino acids that have been joined together through peptide bonding. It is the first level of protein structure and dictates the higher levels of structure that follow.

Answer E is incorrect because while DNA nucleotide sequence codes for the amino acid sequence of a protein, it is not considered part of the protein's primary structure.

Answers A, B, and C refer to higher levels of protein structure (quaternary, secondary, and tertiary, respectively) and are not part of the protein's primary structure.

The Primary Structure of a Protein Refers to the