Question

In reactions mediated by protein kinases, what does phosphorylation of successive proteins do to drive the reaction?

A. make functional ATP
B. change a protein from its inactive to its active form
C. change a protein from its active to its inactive form
D. alter the permeability of the cell's membranes
E. produce an increase in the cell's store of inorganic phosphates

Answer 1

Phosphorylation by protein kinases changes the structural orientation of substrate molecules, activating them and allowing them to mediate changes in cellular processes.

Step-by-step explanation:

Protein kinases transfer a phosphate group from ATP to a substrate molecule in a process called phosphorylation.

This phosphorylation changes the structural orientation of the substrate molecule, thereby activating it. The activated molecules can then mediate changes in cellular processes.