Question

In a globular protein, where will the amino acid that occurs at the C-terminus generally be found?

1) at the protein's surface
2) in the protein's interior
3) in the middle of an α helix
4) in the middle of a β sheet
5) all of these locations

Answer 1

The C-terminus of a globular protein is typically found on the protein's surface due to the folding of the protein, which generally exposes hydrophilic amino acids and hides hydrophobic ones, although there may be exceptions based on protein function.

Step-by-step explanation:

The amino acid located at the C-terminus of a globular protein will generally be found on the protein's surface. In globular proteins, the polypeptide chain folds in a way that usually places hydrophobic (non-polar) amino acids inside the structure and hydrophilic (polar and charged) amino acids on the surface. This orientation helps the protein maintain its functional shape within an aqueous environment. However, the exact location can also be influenced by the protein's function and interaction with other molecules.

It is important to note that while this is a common rule, there are exceptions, and the precise location can vary based on the specific protein's structure and function. Examples of diseases caused by improper protein folding include cystic fibrosis and prion diseases, where misfolding leads to loss of function or harmful accumulations of protein in the body.