Biochemistry - Glycolysis - Discussion

Muscle which contains only hexokinase can use this enzyme to phosphorylate fructose producing F6P which is a direct glycolytic intermediate. In liver the glucokinase, is specific for glucose as a substrate, therefore it requires an alternative enzyme to phosphorylate fructose. Hepatic fructokinase can phosphorylate fructose on C-1 to produce fructose-1-phosphate (F1P).

Instead of F 1,6 biphosphate aldolase , the liver containing aldolase B that can use F1P as a substrate to generate dihdroxyacetone phosphate( DHAP) and glyceraldehyde. The DHAP is converted, by triose phosphate isomerase(TIM), to G3P while the glyceraldehyde is phosphorylated to G3P by triose kinase.

Muscles (skeletal muscles) tend to consume glucose rather than releasing it to the other tissue. They lack glucose-6-phosphate and Glucagon hormone which are essential for completing glycogenolysis to release energy.

Glucose can obtained by Glucose 6 phosphate in liver, which can not obtained by muscle because lack of Glucose 6 phosphate, it just gets Glucose 6 phosphate and continue to Glycolysis.

The enzyme glucose 6 phosphatase is not found in muscles so glucose is not likely to be the end product of glycogenolysis in muscles. Option A is correct.

Answer is right, glycogenolysis occurs in the liver as well as muscles. In muscles instead of glucose g6p is produced.

The correct answer is B because muscle also needs glycogen.

Phosphorylation can lead to glucose only in liver.

According to me, the correct answer is A.