Question

In Glycolysis, fructose-6-phosphate is converted to fructose-1,6-bisphosphate by phosphofructokinase. How many of the following statements are true?

- This step is reversible.
- This step is a point of control.
- It is activated by ATP only.
- Fructose-1,6-bisphosphate is committed to become pyruvate and yield energy.

Group of answer choices:
a. - 3
b. - 2
c. - 4
d. - 1

Answer 1

In glycolysis, the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate by phosphofructokinase is a regulation point and commits the molecule to further metabolism, but the step is not reversible and is not solely activated by ATP. Therefore, the correct answer to the question is b. - 2 statements are true.

Step-by-step explanation:

In glycolysis, the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate by phosphofructokinase is a critical step. Of the given statements, two are true:

• This step is a point of control in the glycolytic pathway.
• Fructose-1,6-bisphosphate is committed to becoming pyruvate and ultimately yields energy through further metabolic processes.

The step is not reversible and is not activated by ATP only, as ATP acts as a substrate but ADP levels impact the enzyme's activity. Phosphofructokinase is regulated by several factors, including the levels of ATP and ADP, and this serves to regulate the flow through glycolysis based on the cell's energy needs.

Therefore, the correct answer to the question is b. - 2 statements are true.