Sickle-cell anemia is caused by a change in a single amino acid in the polypeptide chain.

Question

A change in which level of protein structure accounts for this condition?

Responses

primary
primary

tertiary
tertiary

quaternary
quaternary

secondary

Answer 1

The correct response is primary.

Sickle-cell anemia is caused by a mutation in the gene that encodes the beta chain of hemoglobin, resulting in the substitution of valine for glutamic acid at the sixth position of the polypeptide chain. This change at the level of the amino acid sequence is a change in the primary structure of the protein.