Question

What is the function of a phosphatase?

a. A phosphatase removes phosphorylated amino acids from proteins.

b. A phosphatase removes the phosphate group from phosphorylated amino acid residues in a protein.

c. A phosphatase phosphorylates serine, threonine, and tyrosine residues.

d. A phosphatase degrades second messengers in the cell.

Short answer

The correct answer is option (b).

Step-by-step solution

Introduction

To create a physiological response, certain cellular proteins should be activated or deactivated to help to spread a signal through the cytoplasm. The protein activation and deactivation mainly depends on its phosphorylation ,which is done by different enzyme activities.

Explanation for the correct answer

Protein phosphatases have the opposite function of protein kinases. While the phosphate groups are attached to specific amino acid residues of the target proteins by the actions of protein kinases, phosphatases serve exactly opposite functions. A phosphatase is an enzyme that removes a phosphate group from amino acid residues of a protein.

Hence, option (b) is correct.

Explanation for the incorrect options

Phosphatases only remove the phosphate groups , but they are unable to remove the bound amino acid residues. Hence, option (a) is wrong.

Phosphatases can't phosphorylate any amino acids. Phosphorylation of amino acid is done by kinase enzymes. Hence, option (c) is wrong.

A phosphatase can't degrade second messengers. Hence, option (d) is incorrect.