Question 1

Which of the following statements best describes the difference between anabolic and catabolic pathways in cellular metabolism?

Accepted Answer

Anabolic pathways synthesize cellular components and require energy, while catabolic pathways break down cellular components and release energy.

Question 2

The hydrolysis of ATP to ADP and inorganic phosphate ($$ATP + H_2O \rightarrow ADP + P_i + H^+) is $$highly exergonic. Which of the following is NOT a reason for this?

Accepted Answer

Decrease in entropy and solubility of the products.

Question 3

Which molecule has the highest standard free energy of hydrolysis ($$\Delta G^\circ') $$among the following?

Accepted Answer

Phosphoenolpyruvate (PEP)

Question 4

During glycolysis, which enzyme catalyzes the first ATP-generating event?

Accepted Answer

Phosphoglycerate kinase

Question 5

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

Accepted Answer

To regenerate NAD+ from NADH, allowing glycolysis to continue.

Question 6

Which of the following reactions represents the reduction of NAD+ during glycolysis?

Accepted Answer

$$NAD^+ + 2[H] \rightarrow NADH + H^+$$

Question 7

A patient presents with muscle fatigue and soreness after intense exercise. Which metabolic process is most likely responsible for the accumulation of lactate in their muscles?

Accepted Answer

Lactate fermentation

Question 8

Which of the following best explains why the hydrolysis of phosphoenolpyruvate (PEP) is more exergonic than the hydrolysis of ATP?

Accepted Answer

PEP hydrolysis results in a product (pyruvate) that undergoes tautomerization, further stabilizing it.

Question 9

Which of the following statements about mitochondria is TRUE?

Accepted Answer

Mitochondria contain their own DNA and protein synthesis machinery.

Question 10

In aerobic respiration, what is the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen ($$O_2)$$

Question 11

Which of the following is a direct product of glycolysis per molecule of glucose?

Accepted Answer

2 ATP, 2 NADH, and 2 pyruvate

Question 12

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

ATP synthesis driven by the transfer of a phosphate group directly from a high-energy substrate to ADP.

Question 13

Which enzyme catalyzes the irreversible conversion of phosphoenolpyruvate (PEP) to pyruvate in glycolysis?

Accepted Answer

Pyruvate kinase

Question 14

A cell is performing glycolysis in the absence of oxygen. What is the fate of the NADH produced during glycolysis?

Accepted Answer

It is reoxidized to NAD+ by transferring electrons to pyruvate or its derivatives.

Question 15

Which of the following statements about fermentation is FALSE?

Accepted Answer

Fermentation completely oxidizes glucose to carbon dioxide and water.

Question 16

Which of the following is NOT a function of the mitochondrial matrix?

Accepted Answer

Electron transport chain

Question 17

Which of the following best explains why cells cluster mitochondria in regions with high ATP demand?

Accepted Answer

Mitochondria generate ATP through oxidative phosphorylation, meeting local energy needs.

Question 18

Which of the following is a correct net equation for glycolysis?

Accepted Answer

$$Glucose + 2NAD^+ + 2ADP + 2P_i \rightarrow 2Pyruvate + 2NADH + 2H^+ + 2ATP$$

Question 19

Which of the following statements about the F$$_1F$_0$$ ATP synthase complex in mitochondria is TRUE?

Accepted Answer

It synthesizes ATP using the proton gradient across the inner mitochondrial membrane.

Cellular Energetics and Metabolic Pathways: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard