$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \mathrm{H}^+$$ \\ \Delta G^\circ = -7.3\ \text{kcal/mol}$

Question 1

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP is an energy coupler, linking exergonic and endergonic reactions.

Question 2

During glycolysis, which step is directly responsible for the net production of ATP?

Accepted Answer

Step 7: 1,3-bisphosphoglycerate → 3-phosphoglycerate

Question 3

Which equation represents the hydrolysis of ATP and its standard free energy change?

Accepted Answer

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} ightarrow \mathrm{ADP} + \mathrm{P}_i + \mathrm{H}^+$$ \ \Delta G^\circ = -7.3\ 	ext{kcal/mol}$

Question 4

Which enzyme is responsible for catalyzing the conversion of glucose to glucose-6-phosphate in glycolysis?

Accepted Answer

Hexokinase

Question 5

In the absence of oxygen, what is the primary purpose of fermentation in cells?

Accepted Answer

To regenerate NAD+ for glycolysis to continue

Question 6

Which of the following statements about catabolic and anabolic pathways is correct?

Accepted Answer

Catabolic pathways are exergonic and release energy.

Question 7

What is the net ATP yield from glycolysis per molecule of glucose?

Accepted Answer

2 ATP

Question 8

Which molecule acts as the most common coenzyme in cellular oxidation reactions?

Accepted Answer

NAD+

Question 9

Which step in glycolysis is regulated by ATP and is considered a key regulatory point?

Accepted Answer

Step 3: Phosphofructokinase-1

Question 10

During strenuous exercise, muscle cells switch to anaerobic respiration. What is a likely consequence?

Accepted Answer

Buildup of lactic acid and decreased blood pH

Question 11

Which of the following equations correctly represents the overall reaction for aerobic glucose catabolism?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\ \mathrm{O}_2 \rightarrow 6\ \mathrm{CO}_2 + 6\ \mathrm{H}_2\mathrm{O}$$

Question 12

Which enzyme is used in gluconeogenesis to bypass the irreversible step catalyzed by pyruvate kinase in glycolysis?

Accepted Answer

Pyruvate carboxylase and phosphoenolpyruvate carboxykinase

Question 13

Which of the following best explains why ATP hydrolysis is highly exergonic?

Accepted Answer

ATP has phosphoanhydride bonds with strong charge repulsion and the products are stabilized by resonance.

Question 14

Which molecule is produced during glycolysis and can enter fermentation pathways under anaerobic conditions?

Accepted Answer

Pyruvate

Question 15

Which of the following is a correct description of the role of NAD+ in glycolysis?

Accepted Answer

NAD+ accepts electrons during the oxidation of glyceraldehyde-3-phosphate.

Question 16

Which of the following best describes the effect of insulin on glycolysis?

Accepted Answer

Insulin promotes glycolysis by increasing glucose uptake into cells.

Question 17

A patient with lactic acidosis is likely experiencing which of the following?

Accepted Answer

Buildup of lactic acid due to anaerobic glycolysis

Question 18

Which step in glycolysis is catalyzed by phosphofructokinase-1 and is regulated by ATP and AMP?

Accepted Answer

Fructose-6-phosphate → Fructose-1,6-bisphosphate

Question 19

Which of the following is a real-world example of fermentation used in food production?

Accepted Answer

Production of yogurt by lactic acid bacteria

Question 20

Which of the following best describes the relationship between glycolysis and gluconeogenesis?

Accepted Answer

Gluconeogenesis reverses glycolysis but uses different enzymes for irreversible steps.

Glycolysis, Fermentation, and Regulation of Energy Metabolism

Guida di studio - Domande di pratica