$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$$

Question 1

Which of the following best describes the main purpose of cellular respiration in eukaryotic cells?

Accepted Answer

To break down glucose and other organic molecules to produce ATP for cellular work.

Question 2

During glycolysis, what is the net gain of ATP and NADH molecules per molecule of glucose?

Accepted Answer

$$2$$ ATP and $$2$$ NADH

Question 3

Which of the following statements about the Krebs cycle (citric acid cycle) is correct?

Accepted Answer

It completes the oxidation of glucose by breaking down acetyl CoA into carbon dioxide.

Question 4

What is the primary role of oxygen in cellular respiration?

Accepted Answer

To accept electrons at the end of the electron transport chain, forming water.

Question 5

A muscle cell is deprived of oxygen but continues to produce ATP. Which process is most likely occurring?

Accepted Answer

Lactic acid fermentation in the cytosol.

Question 6

Which of the following equations correctly represents the overall process of cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{Energy}$$

Question 7

Which of the following best explains why fermentation is less efficient than aerobic respiration?

Accepted Answer

Fermentation only partially oxidizes glucose, resulting in less ATP production.

Question 8

In the electron transport chain, the energy from electrons is used to:

Accepted Answer

Pump protons across the inner mitochondrial membrane, creating a proton gradient.

Question 9

Which of the following is a correct comparison between strict (obligate) aerobes and strict (obligate) anaerobes?

Accepted Answer

Obligate aerobes require oxygen for growth, while obligate anaerobes cannot survive in the presence of oxygen.

Question 10

A cell is performing glycolysis and fermentation. Which molecule must be regenerated to allow glycolysis to continue?

Accepted Answer

NAD+

Question 11

Which of the following processes produces the greatest number of ATP molecules per glucose during cellular respiration?

Accepted Answer

Electron transport chain and oxidative phosphorylation

Question 12

If a poison blocks the function of ATP synthase, which of the following would be directly affected?

Accepted Answer

The synthesis of ATP from ADP and $$P_i$$ during oxidative phosphorylation

Question 13

Which of the following is a product of lactic acid fermentation?

Accepted Answer

Lactate

Question 14

Which step in cellular respiration occurs in the cytosol of the cell?

Accepted Answer

Glycolysis

Question 15

A patient has a genetic defect that prevents the formation of FADH$$_2. $$Which stage of cellular respiration would be most directly affected?

Accepted Answer

Krebs cycle

Question 16

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

ATP production by direct enzymatic transfer of a phosphate group to ADP from an intermediate substrate.

Question 17

Which of the following is a key difference between aerobic and anaerobic respiration?

Accepted Answer

Aerobic respiration uses oxygen as the final electron acceptor, while anaerobic respiration does not.

Question 18

If a cell is unable to regenerate NAD$$^+$$, which process will stop first?

Accepted Answer

Glycolysis

Question 19

Which of the following best explains why fats produce more ATP per gram than carbohydrates during cellular respiration?

Accepted Answer

Fats have more carbon-hydrogen bonds, which release more electrons for the electron transport chain.

Question 20

A facultative anaerobe is placed in an environment with no oxygen. Which pathway will it use to generate ATP?

Accepted Answer

Fermentation

Lecture 8 - Cellular Respiration: Mechanisms, Pathways, and Comparisons

Guida di studio - Domande di pratica