Question

. In the primary sequence of a protein, a valine is substituted in place of a glutamic acid. Which of the following statements is true? a. This is a transition from a non-polar amino acid to a polar amino acid. b. This will affect the secondary protein structure. c. This is a transition from a hydrophobic amino acid to a hydrophilic amino acid. d. This will have no effect on the protein. e. This is a silent mutation.

Answer 1

The following statements that are true-

a. This is a transition from a non-polar amino acid to a polar amino acid.

b. This will affect the secondary protein structure.

c. This is a transition from a hydrophobic amino acid to a hydrophilic amino acid.

All the 3 options are correct but if you have to select a single option then the answer is-

b. This will affect the secondary protein structure.

Valine is a non polar, hydrophobic amino acid where as Glutamic acid is polar, hydrophilic amino acid. All polar things can form hydrogen bond with water that is why they are more soluble in water.

And non polar, hydrophobic amino acids tend to cluster together within proteins. These amino acids makes the interior of the protein and gives stability to the protein structure through hydrophobic interactions. So substitution of valine with glutamic acid will affect the protein secondary sructure as it will alter stability.