DAT Biology: Cellular Metabolism 2

Question 1

During glycolysis, which molecule is the direct net product of substrate-level phosphorylation per glucose?

Accepted Answer

2 net ATP

Answer

Glycolysis produces 4 ATP but consumes 2 in the investment phase, for a net of 2 ATP.

Question 2

Which enzyme catalyzes the committed, rate-limiting step of glycolysis?

Accepted Answer

Phosphofructokinase-1

Answer

PFK-1 catalyzes the irreversible, allosterically regulated committed step of glycolysis.

Question 3

Under anaerobic conditions in human muscle, pyruvate is converted to what to regenerate NAD+?

Accepted Answer

Lactate

Answer

Lactate dehydrogenase reduces pyruvate to lactate, oxidizing NADH back to NAD+ for glycolysis to continue.

Question 4

Where does glycolysis occur within the eukaryotic cell?

Accepted Answer

Cytoplasm

Answer

Glycolysis takes place entirely in the cytosol, requiring no membrane-bound organelle.

Question 5

How many carbon atoms does each pyruvate molecule contain?

Accepted Answer

3

Answer

Glucose (6 carbons) is split into two 3-carbon pyruvate molecules.

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