Both water and glucose share an -OH that can serve as a substrate for a reaction with the terminal phosphate of ATP catalyzed by hexokinase.Glucose,however,is about a million times more reactive as a substrate than water.The best explanation is that:
A)glucose has more -OH groups per molecule than does water.
B)the larger glucose binds better to the enzyme;it induces a conformational change in hexokinase that brings active-site amino acids into position for catalysis.
C)the -OH group of water is attached to an inhibitory H atom,while the glucose -OH group is attached to C.
D)water and the second substrate,ATP,compete for the active site resulting in a competitive inhibition of the enzyme.
E)water normally will not reach the active site because it is hydrophobic.

Question

Quizplus · Accepted Answer

The larger size of glucose allows for better binding to the enzyme, inducing a conformational change that brings active-site amino acids into position for catalysis. This increased binding affinity results in glucose being a better substrate for the enzyme than water.

Both Water and Glucose Share an -OH That Can Serve