Q: Which of the following best describes the overall net reaction of glycolysis?

$$\text{Glucose} + 2 \text{Pi} + 2 \text{ADP} + 2 \text{NAD}^+ \rightarrow 2 \text{Pyruvate} + 2 \text{ATP} + 2 \text{NADH} + 2 \text{H}^+ + 2 \text{H}_2\text{O}$$

Q: What is the primary purpose of fermentation in the context of glycolysis?

To regenerate $$\text{NAD}^+ so $$glycolysis can continue

Q: If a cell is deprived of oxygen, what will happen to the pyruvate produced by glycolysis?

It will undergo fermentation to regenerate $$\text{NAD}^+$$

Question 1

Which of the following best describes the overall net reaction of glycolysis?

Accepted Answer

$$	ext{Glucose} + 2 	ext{Pi} + 2 	ext{ADP} + 2 	ext{NAD}^+ ightarrow 2 	ext{Pyruvate} + 2 	ext{ATP} + 2 	ext{NADH} + 2 	ext{H}^+ + 2 	ext{H}_2	ext{O}$$

Question 2

Which enzyme is responsible for the phosphorylation of glucose in the first step of glycolysis?

Accepted Answer

Hexokinase

Question 3

During glycolysis, which step is regulated as the main control point and why?

Accepted Answer

Step 3, because phosphofructokinase activity determines the rate of glycolysis

Question 4

What is the primary purpose of fermentation in the context of glycolysis?

Accepted Answer

To regenerate $$	ext{NAD}^+ so $$glycolysis can continue

Question 5

Which of the following is a correct description of substrate-level phosphorylation in glycolysis?

Accepted Answer

A phosphate group is directly transferred from a high-energy intermediate to ADP, forming ATP

Question 6

If a cell is deprived of oxygen, what will happen to the pyruvate produced by glycolysis?

Accepted Answer

It will undergo fermentation to regenerate $$	ext{NAD}^+$$

Question 7

Which molecule is produced in glycolysis and is essential for the electron transport chain under aerobic conditions?

Accepted Answer

NADH

Question 8

A mutation in the gene encoding triosephosphate isomerase would most directly affect which step of glycolysis?

Accepted Answer

Conversion of dihydroxyacetone phosphate (DHAP) to glyceraldehyde 3-phosphate (G3P)

Question 9

Which of the following best explains why glycolysis is considered an anaerobic process?

Accepted Answer

It does not require oxygen to proceed

Question 10

How many net ATP molecules are produced per molecule of glucose during glycolysis?

Accepted Answer

2

Question 11

Which step in glycolysis involves the oxidation of G3P and the reduction of NAD$$^+$$?

Accepted Answer

Step 6

Question 12

In muscle cells during intense exercise, which fermentation product is formed to allow glycolysis to continue?

Accepted Answer

Lactic acid

Question 13

Which enzyme catalyzes the final step of glycolysis, converting phosphoenolpyruvate (PEP) to pyruvate?

Accepted Answer

Pyruvate kinase

Question 14

Why is it important for cells to recycle NAD$$^+$$ during glycolysis?

Accepted Answer

Without NAD$$^+$$, glycolysis would stop because G3P could not be oxidized

Question 15

Which of the following is NOT a product of glycolysis?

Accepted Answer

CO$$_2$$

Question 16

A patient has a genetic defect in phosphofructokinase. Which of the following would most likely occur?

Accepted Answer

Glycolysis would slow down or stop due to inability to phosphorylate fructose-6-phosphate

Question 17

Which of the following best describes the fate of pyruvate in yeast cells under anaerobic conditions?

Accepted Answer

It is converted to ethanol and CO$$_2$$

Question 18

Which step in glycolysis is catalyzed by an isomerase enzyme?

Accepted Answer

Conversion of glucose-6-phosphate to fructose-6-phosphate

Question 19

If a cell runs out of NAD$$^+$$, which step of glycolysis would be directly affected first?

Accepted Answer

Oxidation of glyceraldehyde 3-phosphate (G3P)

Question 20

Which of the following statements about the energy investment and energy payoff phases of glycolysis is correct?

Accepted Answer

The energy investment phase uses 2 ATP, while the energy payoff phase produces 4 ATP and 2 NADH

Glycolysis: The First Stage of Cellular Respiration

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