Question

In the first step of glycolysis, glucose can be phosphorylated to glucose-6-phosphate, because

A) a phosphoanhydride bond has higher energy of hydrolysis than is required for formation of a phosphoester bond.
B) transfer of a phosphate from ATP to glucose is endergonic.
C) the reaction does not require an enzyme.
D) the reaction is highly reversible.
E) All of the above are correct.

Answer 1

The phosphorylation of glucose to glucose-6-phosphate in glycolysis occurs because the energy from the hydrolysis of the high-energy phosphoanhydride bond in ATP is greater than the energy needed to form the phosphoester bond on glucose-6-phosphate.

Step-by-step explanation:

The correct answer to the question "In the first step of glycolysis, why can glucose be phosphorylated to glucose-6-phosphate?" is A) a phosphoanhydride bond has higher energy of hydrolysis than is required for formation of a phosphoester bond. This is because the energy from the hydrolysis of ATP, which has a phosphoanhydride bond, is used to add a phosphate group to glucose, forming a phosphoester bond in glucose-6-phosphate. This reaction is catalyzed by the enzyme hexokinase, and it is essential in trapping glucose within the cell and increasing its reactivity for further steps in glycolysis.

Glycolysis is a series of enzymatic reactions that begin with the phosphorylation of glucose by hexokinase to form glucose-6-phosphate. This initial step uses the energy from ATP hydrolysis to add a phosphate group to the glucose molecule. The result is a more reactive glucose molecule, which can then undergo further metabolic changes during glycolysis. Following this step, a series of reactions lead to the production of pyruvate and ATP, as well as the reduction of NAD+ to NADH.