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Biology

Biology · Bioenergetics

Work through this past-paper style MCQ, then read the full explanation. Practice more biology questions on mMCQ with adaptive practice and topic analytics.

Question

Phosphofructokinases enzyme converts fructose-6-phosphate into:

Options
  • A

    Fructose-1,4-phosphate

  • B

    Fructose-1,6-bisphosphate

  • C

    Bisphosphate

  • D

    Fructose

Explanation

Phosphofructokinase (PFK) plays a critical role in glycolysis by catalyzing the conversion of fructose-6-phosphate into fructose-1,6-bisphosphate. This reaction involves the transfer of a phosphate group from ATP to fructose-6-phosphate, forming fructose-1,6-bisphosphate and ADP. This step is key for regulating the glycolytic pathway. Option B is correct because it reflects the specific phosphorylated product of this reaction. Option A is incorrect because it specifies the wrong positions for phosphorylation. Option C is too vague, as it does not specify the positions of the phosphate groups. Option D is incorrect because it suggests a conversion that does not occur in this enzymatic reaction.

This is incorrect. Phosphofructokinase does not produce fructose-1,4-phosphate, as it phosphorylates at positions 1 and 6.

This is correct. Phosphofructokinase catalyzes the addition of a phosphate group to both position 1 and position 6 of fructose-6-phosphate, resulting in fructose-1,6-bisphosphate.

This is incorrect due to lack of specificity. The precise product is fructose-1,6-bisphosphate, highlighting the positions of the phosphate groups.

This is incorrect. Phosphofructokinase modifies fructose-6-phosphate by adding phosphate groups, not by converting it into free fructose.

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Tagged under Biology · Bioenergetics