Cell Respiration Quizzes: Master the Energy Production Process

Question 1

In which part of a mitochondrion does oxidative phosphorylation occur?

Accepted Answer

Inner mitochondrial membrane

Answer

Matrix

Answer

Outer mitochondrial membrane

Question 2

What is the primary end product of glycolysis?

Accepted Answer

Pyruvate

Answer

Lactate

Answer

Acetyl-CoA

Answer

ATP

Question 3

Which of the following is NOT a step where substrate-level phosphorylation occurs during cellular respiration?

Accepted Answer

Oxidative phosphorylation via ATP synthase

Answer

Conversion of phosphoglycerate to phosphoenolpyruvate

Answer

Conversion of succinyl-CoA to succinate

Answer

Conversion of malate to oxaloacetate

Question 4

What is the primary function of NADH dehydrogenase in the electron transport chain?

Accepted Answer

To transfer electrons from NADH to the electron transport chain

Answer

To pump protons across the inner mitochondrial membrane

Answer

To reduce oxygen to water

Answer

To synthesize ATP via ATP synthase

Question 5

Which of the following factors does NOT influence the rate of cellular respiration?

Accepted Answer

Hormonal regulation

Answer

Temperature

Answer

Oxygen availability

Answer

Concentration of reactants

Question 6

Which substance serves as the ultimate electron acceptor in the electron transport chain?

Accepted Answer

Oxygen

Answer

Carbon dioxide

Answer

Glucose

Answer

Pyruvate

Question 7

What is the primary function of glycolysis in cellular respiration?

Accepted Answer

To convert glucose into pyruvate

Answer

To generate ATP

Answer

To produce NADH and FADH2

Answer

To release carbon dioxide

Question 8

What is the primary purpose of the proton gradient formed during the electron transport chain?

Accepted Answer

To generate ATP

Answer

To transfer NADH and FADH2

Answer

To reduce oxygen

Answer

To release carbon dioxide

Question 9

Which of the following is not a stage in the Krebs cycle?

Accepted Answer

Electron transport

Answer

Citric acid formation

Answer

Isocitrate oxidation

Answer

Succinyl-CoA synthesis

Question 10

In aerobic respiration, what is the approximate number of ATP molecules produced per glucose molecule?

Accepted Answer

36-38

Answer

2

Answer

6

Answer

12

Question 11

Which factor does not influence the rate of cellular respiration?

Accepted Answer

Light intensity

Answer

Substrate concentration

Answer

Enzyme concentration

Answer

Temperature

Question 12

What is the primary purpose of anaerobic respiration?

Accepted Answer

ATP generation without oxygen

Answer

Carbon dioxide and water production

Answer

Glucose breakdown into pyruvate

Answer

NADH and FADH2 production

Question 13

In yeast, which product is formed during fermentation?

Accepted Answer

Ethanol

Answer

Lactic acid

Answer

Carbon dioxide

Answer

ATP

Question 14

Which metabolic pathway occurs within the cytosol?

Accepted Answer

Glycolysis

Answer

Krebs cycle

Answer

Electron transport chain

Answer

Oxidative phosphorylation

Question 15

What is the significance of chemiosmosis in cellular respiration?

Accepted Answer

Proton gradient formation for ATP synthesis

Answer

Electron transport across the mitochondrial membrane

Answer

NADH and FADH2 production

Answer

Glucose breakdown into pyruvate

Question 16

In glycolysis, which molecule serves as the primary energy source?

Accepted Answer

Glucose

Answer

Pyruvate

Answer

Acetyl-CoA

Answer

Lactate

Question 17

During the Krebs cycle, which intermediate undergoes decarboxylation twice?

Accepted Answer

Isocitrate

Answer

Citrate

Answer

Alpha-ketoglutarate

Answer

Oxaloacetate

Question 18

Which enzyme facilitates electron transfer from NADH to ubiquinone within the electron transport chain?

Accepted Answer

NADH dehydrogenase

Answer

ATP synthase

Answer

Cytochrome oxidase

Answer

Succinate dehydrogenase

Question 19

Under conditions of limited oxygen availability, pyruvate is converted into:

Accepted Answer

Lactate

Answer

Acetyl-CoA

Answer

Carbon dioxide

Answer

Water

Question 20

Which substance is NOT produced as an end product of aerobic cellular respiration?

Accepted Answer

NADH

Answer

ATP

Answer

Carbon dioxide

Answer

Water

Question 21

Which statement about the Krebs cycle is incorrect?

Accepted Answer

It directly produces GTP.

Answer

It occurs within the mitochondrial matrix.

Answer

It generates carbon dioxide as a byproduct.

Answer

It is an oxygen-dependent process.

Question 22

What is the electron transport chain's primary function?

Accepted Answer

Proton pumping across the mitochondrial inner membrane

Answer

ATP generation

Answer

NADH reduction

Answer

Glucose oxidation

Question 23

Why is anaerobic respiration crucial for muscle cells during intense exercise?

Accepted Answer

It allows muscle cells to rapidly generate ATP in low-oxygen conditions.

Answer

It produces more ATP than aerobic respiration.

Answer

It is more efficient than aerobic respiration.

Answer

It prevents muscle fatigue.

Question 24

Which stage of cellular respiration is responsible for the initial breakdown of glucose into two pyruvate molecules?

Accepted Answer

Glycolysis

Answer

Krebs cycle

Answer

Electron transport chain

Answer

Oxidative phosphorylation

Question 25

What is a potential outcome of impaired cellular respiration in muscle cells?

Accepted Answer

Lactic acid accumulation

Answer

Increased ATP production

Answer

Enhanced oxygen consumption

Answer

Improved mitochondrial function

Question 26

The Krebs cycle occurs in the:

Accepted Answer

Mitochondrial matrix

Answer

Cytoplasm

Answer

Mitochondrial inner membrane

Answer

Nucleus

Question 27

Which of the following conditions would result in anaerobic respiration?

Accepted Answer

Limited oxygen supply

Answer

Abundant oxygen supply

Answer

High glucose concentration

Answer

High pH

Question 28

Which of the following enzymes catalyses the conversion of pyruvate to acetyl-CoA?

Accepted Answer

Pyruvate dehydrogenase

Answer

Citrate synthase

Answer

Succinate dehydrogenase

Answer

Lactate dehydrogenase

Question 29

Which of the following best describes the first stage of cellular respiration?

Accepted Answer

Glycolysis

Answer

Krebs cycle

Answer

Electron transport chain

Answer

Oxidative phosphorylation

Question 30

What is the primary product of glycolysis?

Accepted Answer

Pyruvate

Answer

Glucose

Answer

ATP

Answer

NADH

Question 31

Which of the following cellular compartments hosts glycolysis?

Accepted Answer

Cytoplasm

Answer

Mitochondria

Answer

Nucleus

Answer

Endoplasmic reticulum

Question 32

Which molecule serves as the substrate for the Krebs cycle?

Accepted Answer

Acetyl-CoA

Answer

Glucose

Answer

Pyruvate

Answer

NADH

Question 33

Under which condition does anaerobic respiration occur?

Accepted Answer

Absence of oxygen

Answer

Presence of oxygen

Answer

High glucose concentration

Answer

Low pH

Question 34

What is the primary role of NADH and FADH2 in cellular respiration?

Accepted Answer

Electron carriers

Answer

Energy storage molecules

Answer

Reactants in the Krebs cycle

Answer

Substrates for ATP synthase

Question 35

Which of the following equations accurately represents the overall chemical equation for cellular respiration?

Accepted Answer

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

Answer

C6H12O6 + 6CO2 → 6O2 + 6H2O + Energy

Answer

6C6H12O6 + 6O2 → 6CO2 + 6H2O + 36ATP

Answer

6CO2 + 6H2O → C6H12O6 + 6O2 + Energy

Question 36

Which molecule is the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen

Answer

NADH

Answer

FADH2

Answer

ATP

Question 37

What is the primary function of NADH and FADH2 in cellular respiration?

Accepted Answer

To carry electrons from the Krebs cycle to the electron transport chain

Answer

To carry electrons from glycolysis to the Krebs cycle

Answer

To generate ATP directly through substrate-level phosphorylation

Answer

To provide energy for the active transport of molecules across cell membranes

Question 38

Which of the following is not a product of anaerobic respiration in yeast?

Accepted Answer

Lactic acid

Answer

Ethanol

Answer

Carbon dioxide

Answer

Water

Question 39

What is the significance of chemiosmosis in cellular respiration?

Accepted Answer

It generates ATP by allowing protons to flow back across the inner mitochondrial membrane.

Answer

It provides the energy to pump protons across the inner mitochondrial membrane.

Answer

It allows for the direct transfer of electrons between NADH and oxygen.

Answer

It is the process by which glucose breaks down into pyruvate.

Question 40

What is the name of the enzyme that catalyzes the conversion of pyruvate to acetyl-CoA?

Accepted Answer

Pyruvate dehydrogenase

Answer

Citrate synthase

Answer

Succinate dehydrogenase

Answer

Cytochrome c oxidase

Question 41

What is the role of ATP synthase in cellular respiration?

Accepted Answer

To synthesize ATP from ADP and inorganic phosphate.

Answer

To pump protons across the inner mitochondrial membrane.

Answer

To transfer electrons from NADH to oxygen.

Answer

To break down glucose into pyruvate.

Question 42

Which of the following is not a primary stage of aerobic cellular respiration?

Accepted Answer

Pyruvate fermentation

Answer

Glycolysis

Answer

Krebs cycle

Answer

Electron transport chain

Question 43

During glycolysis, glucose is converted into:

Accepted Answer

Two molecules of pyruvate

Answer

Two molecules of lactate

Answer

Two molecules of ATP

Answer

Two molecules of FADH2

Question 44

In the Krebs cycle, which molecule is fully oxidized, releasing carbon dioxide?

Accepted Answer

Acetyl CoA

Answer

Pyruvate

Answer

Citrate

Answer

Oxaloacetate

Question 45

Which of the following is the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen

Answer

NAD+

Answer

Water

Answer

Carbon dioxide

Question 46

Which of the following conditions would initiate anaerobic respiration?

Accepted Answer

Limited oxygen availability

Answer

Sufficient oxygen availability

Answer

Presence of light

Answer

Absence of mitochondria

Question 47

Which of the following molecules is produced as a result of lactic acid fermentation?

Accepted Answer

Lactate

Answer

Pyruvate

Answer

Acetyl CoA

Answer

ATP

Question 48

What is the function of NAD+ and FAD+ in cellular respiration?

Accepted Answer

Electron carriers

Answer

Energy storage molecules

Answer

Catalysts for enzyme reactions

Answer

Waste products of respiration