Cell Metabolism Quizzes: Test Your Understanding of Cellular Processes

Question 1

Which enzyme is responsible for catalyzing the irreversible conversion of pyruvate to acetyl-CoA?

Accepted Answer

Pyruvate dehydrogenase

Answer

Citrate synthase

Answer

Isocitrate dehydrogenase

Answer

α-Ketoglutarate dehydrogenase

Question 2

Identify the primary product of oxidative phosphorylation:

Accepted Answer

ATP

Answer

NADH

Answer

FADH2

Answer

CO2

Question 3

What is the primary function of coenzymes in metabolic reactions?

Accepted Answer

To accept or donate electrons or functional groups

Answer

To provide energy for the reaction

Answer

To act as catalysts

Answer

To regulate enzyme activity

Question 4

What is the primary role of the electron transport chain in oxidative phosphorylation?

Accepted Answer

To establish a proton gradient across the mitochondrial membrane

Answer

To generate ATP

Answer

To reduce NADH and FADH2

Answer

To oxidize glucose

Question 5

Identify an example of a competitive inhibitor:

Accepted Answer

Malonate

Answer

Cyanide

Answer

ATP

Answer

ADP

Question 6

What is the primary role of ATP in metabolic reactions?

Accepted Answer

To provide energy for energy-requiring reactions

Answer

To act as a coenzyme

Answer

To regulate enzyme activity

Answer

To store genetic information

Question 7

In cellular respiration, which process yields the highest number of ATP molecules per glucose molecule?

Accepted Answer

Oxidative Phosphorylation

Answer

Glycolysis

Answer

Krebs Cycle

Question 8

In glycolysis, the initial step involves:

Accepted Answer

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

Answer

Disintegration of glucose into two molecules of pyruvate

Answer

Formation of ATP

Answer

Generation of two NADH molecules

Question 9

The final electron acceptor in oxidative phosphorylation is:

Accepted Answer

Oxygen

Answer

NAD+

Answer

FAD

Answer

Cytochrome c

Question 10

Which enzyme catalyzes the conversion of pyruvate to acetyl-CoA?

Accepted Answer

Pyruvate dehydrogenase

Answer

Citrate synthase

Answer

Isocitrate dehydrogenase

Answer

α-ketoglutarate dehydrogenase

Question 11

Enzymes do NOT perform which of the following functions?

Accepted Answer

Providing energy for reactions

Answer

Lowering activation energy

Answer

Elevating reaction rate

Answer

Enhancing reaction specificity

Question 12

Glycolysis is primarily characterized as a:

Accepted Answer

Catabolic reaction

Answer

Anabolic reaction

Answer

Redox reaction

Answer

Hydrolysis reaction

Question 13

Which of the following is **not** a product of glycolysis?

Accepted Answer

Acetyl-CoA

Answer

Pyruvate

Answer

ATP

Answer

NADH

Question 14

Which enzyme catalyzes the conversion of pyruvate to acetyl-CoA?

Accepted Answer

Pyruvate dehydrogenase

Answer

Citrate synthase

Answer

Succinate dehydrogenase

Answer

ATP synthase

Question 15

What is the primary function of oxidative phosphorylation?

Accepted Answer

To generate ATP

Answer

To produce NADH and FADH2

Answer

To regulate cellular respiration

Answer

To break down glucose

Question 16

What is the primary role of coenzymes in metabolism?

Accepted Answer

To carry electrons

Answer

To activate enzymes

Answer

To provide energy

Answer

To regulate gene expression

Question 17

Which of the following is an example of a catabolic reaction?

Accepted Answer

Glycolysis

Answer

Gluconeogenesis

Answer

Photosynthesis

Answer

Fatty acid synthesis

Question 18

What is the significance of the electron transport chain?

Accepted Answer

It generates a proton gradient used to produce ATP.

Answer

It recycles NADH and FADH2.

Answer

It produces oxygen.

Answer

It regulates cell division.

Question 19

Which of the following organelles is the primary site of cellular respiration?

Accepted Answer

Mitochondria

Answer

Chloroplasts

Answer

Ribosomes

Answer

Lysosomes

Question 20

What is the initial step in the metabolic process known as glycolysis?

Accepted Answer

Phosphorylation of the glucose molecule

Answer

Isomerization of glucose-6-phosphate

Answer

Cleavage of fructose-1,6-bisphosphate

Answer

Oxidation of pyruvate

Question 21

Which enzyme is responsible for catalyzing the conversion of acetyl-CoA to citrate in the Krebs cycle?

Accepted Answer

Citrate synthase

Answer

Aconitase

Answer

Isocitrate dehydrogenase

Answer

Alpha-ketoglutarate dehydrogenase

Question 22

What is the primary purpose of oxidative phosphorylation in cellular metabolism?

Accepted Answer

To generate molecules of ATP

Answer

To reduce NADH and FADH2

Answer

To break down glucose

Answer

To regulate the Krebs cycle

Question 23

Which of the following is not a component of the electron transport chain?

Accepted Answer

ATP synthase

Answer

Cytochrome c

Answer

Complex I

Answer

Ubiquinone

Question 24

What is the primary role of ATP in cellular metabolism?

Accepted Answer

Energy currency

Answer

Signal molecule

Answer

Structural component

Answer

Enzyme cofactor

Question 25

Which step initiates glycolysis?

Accepted Answer

Glucose phosphorylation

Answer

Pyruvate formation

Answer

Splitting of glucose into two glyceraldehyde-3-phosphate molecules

Answer

Oxidation of NADH to NAD+

Question 26

Which enzyme is not involved in oxidative phosphorylation?

Accepted Answer

Hexokinase

Answer

ATP synthase

Answer

Cytochrome oxidase

Answer

Succinate dehydrogenase

Question 27

What is the primary product of glycolysis?

Accepted Answer

Pyruvate

Answer

Acetyl-CoA

Answer

NADH

Answer

FADH2

Question 28

What role do NAD+ and FAD+ play in cellular respiration?

Accepted Answer

Electron carriers

Answer

Electron donors to oxygen

Answer

ATP synthesis

Answer

Enzyme activity regulation

Question 29

Which metabolic pathway generates glucose from non-carbohydrate sources?

Accepted Answer

Gluconeogenesis

Answer

Glycolysis

Answer

Glycogenolysis

Answer

Citric acid cycle

Question 30

What is the importance of ATP in cellular metabolism?

Accepted Answer

Primary energy currency of the cell

Answer

Substrate for metabolic reactions

Answer

Gene expression regulation

Answer

Transports molecules across membranes

Question 31

Which of the following is the first step in glycolysis?

Accepted Answer

Phosphorylation of glucose

Answer

Isomerization of glucose-6-phosphate

Answer

Cleavage of fructose-1,6-bisphosphate

Answer

Oxidation of pyruvate

Question 32

What is the role of NADH in the Krebs cycle?

Accepted Answer

Acceptor of electrons

Answer

Donor of electrons

Answer

Coenzyme for pyruvate dehydrogenase

Answer

Activator of citrate synthase

Question 33

Which of the following enzymes catalyzes the conversion of isocitrate to alpha-ketoglutarate in the Krebs cycle?

Accepted Answer

Isocitrate dehydrogenase

Answer

Aconitase

Answer

Alpha-ketoglutarate dehydrogenase

Answer

Succinyl-CoA synthetase

Question 34

Where does oxidative phosphorylation occur in the cell?

Accepted Answer

Mitochondrial inner membrane

Answer

Mitochondrial matrix

Answer

Mitochondrial intermembrane space

Answer

Cytoplasm

Question 35

What is the role of ATP synthase in oxidative phosphorylation?

Accepted Answer

To synthesize ATP from ADP and inorganic phosphate

Answer

To pump protons across the mitochondrial inner membrane

Answer

To transfer electrons from NADH to oxygen

Answer

To regulate the activity of the electron transport chain

Question 36

Which of the following types of pathways is responsible for breaking down complex molecules into simpler ones?

Accepted Answer

Catabolic pathways

Answer

Anabolic pathways

Answer

Amphibolic pathways

Answer

Assimilative pathways

Question 37

Which type of metabolic pathway is involved in the synthesis of large molecules from smaller ones?

Accepted Answer

Anabolic

Answer

Catabolic

Answer

Amphibolic

Answer

Assimilative

Question 38

Which step initiates glycolysis, the first stage of glucose metabolism?

Accepted Answer

Phosphorylation of glucose (addition of a phosphate group)

Answer

Formation of pyruvate

Question 39

In the Krebs cycle, NADH functions as an:

Accepted Answer

Electron carrier

Answer

Energy storage molecule

Question 40

Which of the following is a direct product of oxidative phosphorylation?

Accepted Answer

ATP

Answer

NADH

Question 41

Enzymes play a crucial role in metabolism by:

Accepted Answer

Accelerating chemical reactions

Answer

Provide energy for reactions

Question 42

Anaerobic metabolism is characterized by:

Accepted Answer

The absence of oxygen

Answer

Production of large amounts of ATP

Question 43

A metabolic reaction that involves the breakdown of molecules is known as a:

Accepted Answer

Catabolic reaction

Answer

Synthesis of proteins

Question 44

ATP's significance in cellular metabolism stems from its role as:

Accepted Answer

The universal energy currency

Answer

Storage form of genetic information

Question 45

In the electron transport chain, which molecule receives the final electrons?

Accepted Answer

Oxygen

Answer

Carbon dioxide

Answer

Glucose

Question 46

Which molecule serves as the final electron acceptor in the electron transport chain during oxidative phosphorylation?

Accepted Answer

Oxygen

Answer

FADH2

Answer

Hydrogen

Answer

NADH

Question 47

Glycolysis, the initial stage of cellular respiration, involves the breakdown of which molecule?

Accepted Answer

Glucose

Answer

Acetyl-CoA

Answer

Pyruvate

Answer

ATP

Question 48

Which enzyme is responsible for catalyzing the conversion of pyruvate to acetyl-CoA, a crucial step in the citric acid cycle?

Accepted Answer

Pyruvate dehydrogenase

Answer

Glyceraldehyde-3-phosphate dehydrogenase

Answer

Citrate synthase

Answer

Hexokinase

Question 49

The citric acid cycle, also known as the Krebs cycle, functions within which cellular compartment?

Accepted Answer

Mitochondrial matrix

Answer

Mitochondrial intermembrane space

Answer

Endoplasmic reticulum

Answer

Cytosol

Question 50

Oxidative phosphorylation, a major energy-yielding process, produces which molecule as its primary product?

Accepted Answer

ATP

Answer

Pyruvate

Answer

NADH

Answer

Acetyl-CoA

Question 51

Summarize the overall chemical equation representing cellular respiration.

Accepted Answer

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

Answer

C6H12O6 + 3O2 → 3CO2 + 3H2O

Answer

C6H12O6 → 2C2H5OH + 2CO2

Question 52

Which factor does NOT influence the rate of chemical reactions in biological systems?

Accepted Answer

Altitude

Answer

Enzyme concentration

Answer

Temperature

Answer

pH

Question 53

ATP, the primary energy currency of cells, primarily serves which function?

Accepted Answer

Energy transfer

Answer

Protein synthesis

Answer

Hormone signaling

Answer

Genetic information storage

Question 54

Which of the following is a key intermediate molecule in the citric acid cycle?

Accepted Answer

Citrate

Answer

Glucose

Answer

Glyceraldehyde-3-phosphate

Answer

Pyruvate