Primary structure

Definition

The primary structure of a protein is the unique sequence of amino acids in a polypeptide chain. This sequence determines the protein's final 3D structure and function.

5 Must Know Facts For Your Next Test

1. The primary structure is held together by peptide bonds.
2. A single change in the amino acid sequence can alter a protein's function, potentially leading to diseases.
3. Primary structure is determined directly by the gene encoding the protein.
4. It dictates how the polypeptide will fold into its secondary and tertiary structures.
5. Methods such as mass spectrometry and Edman degradation are used to determine primary structure.

Review Questions

• What type of bond holds the primary structure of a protein together?
• How can a mutation in DNA affect the primary structure of a protein?
• What techniques are used to determine the primary structure of proteins?

Related terms

Secondary Structure:

The local folding of a polypeptide chain into structures like alpha-helices and beta-sheets.

Tertiary Structure:

The overall three-dimensional shape of a single polypeptide chain.

Peptide Bond:

A covalent bond that links amino acids together in a protein's primary structure.