1. Which enzyme catalyzes the phosphorylation of fructose-6-phosphate during glycolysis?
A.
Phosphofructokinase
B.
Hexokinase
C.
Pyruvate kinase
D.
Phosphoglycerate kinase
Correct Answer:
Phosphofructokinase
Explanation:
Phosphofructokinase catalyzes the phosphorylation of fructose-6-phosphate in the glycolytic pathway.
2. What is the substrate acted upon by phosphofructokinase in glycolysis?
A.
Glucose
B.
Fructose-6-phosphate
C.
Fructose-1,6-bisphosphate
D.
Pyruvate
Correct Answer:
Fructose-6-phosphate
Explanation:
Phosphofructokinase uses fructose-6-phosphate as its substrate and adds another phosphate group to it.
3. Which product is formed when phosphofructokinase acts on fructose-6-phosphate?
A.
Glucose-6-phosphate
B.
Fructose-1-phosphate
C.
Fructose-1,6-bisphosphate
D.
Glyceraldehyde-3-phosphate
Correct Answer:
Fructose-1,6-bisphosphate
Explanation:
The phosphofructokinase reaction converts fructose-6-phosphate into fructose-1,6-bisphosphate.
4. Which molecule provides the phosphate group in the phosphofructokinase reaction?
A.
ADP
B.
NAD+
C.
ATP
D.
Pyruvate
Correct Answer:
ATP
Explanation:
ATP donates a phosphate group during the phosphofructokinase reaction and is converted to ADP.
5. What is the other product formed when ATP is used in the phosphofructokinase reaction?
A.
AMP
B.
ADP
C.
NADH
D.
Carbon dioxide
Correct Answer:
ADP
Explanation:
When ATP donates its phosphate group to fructose-6-phosphate, it becomes ADP.
6. How many ATP molecules are consumed in one phosphofructokinase reaction?
A.
None
B.
One
C.
Two
D.
Four
Correct Answer:
One
Explanation:
One ATP molecule is used to phosphorylate fructose-6-phosphate in the phosphofructokinase reaction.
7. Which equation best represents the phosphofructokinase reaction?
A.
Glucose + ATP → Glucose-6-phosphate + ADP
B.
Fructose-6-phosphate + ATP → Fructose-1,6-bisphosphate + ADP
C.
Fructose-1,6-bisphosphate → Pyruvate + ATP
D.
Pyruvate + ADP → Lactate + ATP
Correct Answer:
Fructose-6-phosphate + ATP → Fructose-1,6-bisphosphate + ADP
Explanation:
Phosphofructokinase transfers a phosphate from ATP to fructose-6-phosphate, forming fructose-1,6-bisphosphate and ADP.
8. Phosphofructokinase adds a phosphate group to which position of fructose-6-phosphate?
A.
Position 1
B.
Position 2
C.
Position 4
D.
Position 6
Correct Answer:
Position 1
Explanation:
Phosphofructokinase adds a phosphate group at carbon 1 of fructose-6-phosphate, producing fructose-1,6-bisphosphate.
9. The phosphofructokinase reaction is commonly considered which type of step in glycolysis?
A.
A phosphate-removal step
B.
An ATP-producing step
C.
An ATP-investment step
D.
An oxygen-producing step
Correct Answer:
An ATP-investment step
Explanation:
The reaction consumes one ATP to add a phosphate group, so it is part of the ATP-investment phase of glycolysis.
10. Where does the phosphofructokinase reaction occur in the cell?
A.
Nucleus
B.
Cytoplasm
C.
Mitochondrial matrix
D.
Chloroplast thylakoid
Correct Answer:
Cytoplasm
Explanation:
Phosphofructokinase catalyzes a step of glycolysis, which takes place in the cytoplasm.
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