Question

In a globular protein, where would the amino acid tryptophan most likely be found? Choose one:

A. hydrogen-bonded to cysteine
B. located at the protein's C-terminus
C. exposed at the protein's surface
D. located at the protein's N-terminus
E. buried in the protein's interior

Answer 1

Tryptophan, a hydrophobic amino acid, would most likely be found buried within the interior of a globular protein to maintain the protein's stable structure through hydrophobic interactions.

Step-by-step explanation:

In a globular protein, the amino acid tryptophan, which is an aromatic and nonpolar amino acid, would most likely be found buried in the protein's interior.

This is because globular proteins fold in such a way that the hydrophilic (water-loving) R groups are on the surface of the molecule, while the hydrophobic (water-fearing) R groups, like that of tryptophan, are tucked away inside.

The internal environment protects these hydrophobic amino acids from the aqueous surroundings and enables the protein to maintain a stable three-dimensional structure through hydrophobic interactions and van der Waals forces. The formation of disulfide bonds between cysteine side chains is an exception, as these covalent bonds contribute to the stability of the protein in a different way.