Why are two phosphate groups added to glucose in stage one of glycolysis? A) To destabilize...

Why are two phosphate groups added to glucose in stage one of glycolysis?

A) To destabilize the intermediates in stage one, making the stage two reactions more favorable.

B) To provide all of the phosphate for ATP synthesis during stage two.

C) To increase the net ATP produced from one glucose molecule.

D) To activate the enzymes in stage two.

Solutions

Expert Solution

Answer. (A)

Glycolysis

Glycolysis involves the breakdown of 1 molecule of glucose to form 2 molcules of pyruvate with the net release of 2 ATP.

First, an enzyme hexokinase phosphorylates the glucose molecule to form glucose 6-phosphate. This helps in trapping glucose within the cell as a cell does not have transporters for phosphorylated sugars.

This glucose 6-phosphate is coverted to fructose 6=phosphate by phosphohexose isomerase. The rationale behind this is to form a symmetrical molecule which upon breakdown would yiels 2 3 memebered molecules.

Another phosphate group is added by phosphofructokinase to form fructose 1,6-bisphosphate. This desatbilizes the molecule and so facilitates its breakdown to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate.

gladiator answered 1 year ago

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