Bioenergetics: The Fundamentals of Energy Metabolism

Question 1

Which of the following is the primary substrate for glycolysis?

Accepted Answer

Glucose

Answer

Fructose

Answer

Acetyl-CoA

Answer

Oxaloacetate

Question 2

Which of the following enzymes catalyzes the conversion of pyruvate to acetyl-CoA in the Krebs cycle?

Accepted Answer

Pyruvate dehydrogenase complex

Answer

Isocitrate dehydrogenase

Answer

α-ketoglutarate dehydrogenase complex

Answer

Succinate dehydrogenase

Question 3

What is the role of NADH and FADH2 in oxidative phosphorylation?

Accepted Answer

They carry electrons to the electron transport chain

Answer

They undergo oxidation to produce ATP

Answer

They donate protons to the intermembrane space

Answer

They regulate the activity of ATP synthase

Question 4

Which of the following is the primary molecule that stores and releases energy in cells?

Accepted Answer

ATP

Answer

Glucose

Answer

ADP

Answer

NADH

Question 5

What process involves breaking down glucose without using oxygen?

Accepted Answer

Glycolysis

Answer

Krebs cycle

Answer

Oxidative phosphorylation

Answer

Cellular respiration

Question 6

Which molecule accepts electrons from NADH during oxidative phosphorylation?

Accepted Answer

Coenzyme Q

Answer

Cytochrome c

Answer

Cytochrome oxidase

Answer

ATP synthase

Question 7

Which of the following is NOT a product of the Krebs cycle?

Accepted Answer

Pyruvate

Answer

ATP

Answer

NADH

Answer

FADH2

Question 8

Which enzyme is responsible for converting phosphoenolpyruvate (PEP) to pyruvate in glycolysis?

Accepted Answer

Pyruvate kinase

Answer

Glyceraldehyde-3-phosphate dehydrogenase

Answer

Enolase

Answer

Lactate dehydrogenase

Question 9

What is the primary use of the proton gradient established across the inner mitochondrial membrane during oxidative phosphorylation?

Accepted Answer

Driving ATP synthesis

Answer

Transporting electrons

Answer

Generating heat

Answer

Storing NADH

Question 10

Which enzyme is a key regulatory point in the Krebs cycle?

Accepted Answer

Isocitrate dehydrogenase

Answer

Succinate dehydrogenase

Answer

Fumarase

Answer

Malate dehydrogenase

Question 11

In the electron transport chain, what is the final electron acceptor?

Accepted Answer

Oxygen

Answer

NADH

Answer

FADH2

Answer

Cytochrome c

Question 12

What is the main function of ATP in cellular processes?

Accepted Answer

Energy carrier

Answer

Electron carrier

Answer

Coenzyme

Answer

Substrate

Question 13

In the Krebs cycle, which enzyme plays a critical role in the initial condensation reaction?

Accepted Answer

Citrate synthase

Answer

Glucokinase

Answer

Hexokinase

Answer

Pyruvate dehydrogenase

Question 14

In oxidative phosphorylation, what is the primary function of the chemiosmotic gradient?

Accepted Answer

To facilitate the synthesis of ATP

Answer

To transport electrons

Answer

To generate NADH and FADH2

Answer

To pump ions across the mitochondrial membrane

Question 15

Which metabolic pathway operates under both aerobic and anaerobic conditions?

Accepted Answer

Glycolysis

Answer

Krebs cycle

Answer

Gluconeogenesis

Answer

Oxidative phosphorylation

Question 16

In substrate-level phosphorylation, what is the high-energy intermediate produced?

Accepted Answer

ATP

Answer

ADP

Answer

NADH

Answer

FADH2

Question 17

Which of the following is a fundamental concept of bioenergetics?

Accepted Answer

Energy metabolism and ATP production

Answer

Protein synthesis and DNA replication

Answer

Lipid synthesis and hormone production

Answer

Carbohydrate digestion and amino acid transport

Question 18

The process of cellular respiration begins with:

Accepted Answer

Glycolysis in the cytoplasm

Answer

Krebs cycle in the mitochondria

Answer

Oxidative phosphorylation in the plasma membrane

Answer

Electron transport chain in the nucleus

Question 19

The final electron acceptor in the electron transport chain is:

Accepted Answer

Oxygen

Answer

NADH

Answer

FADH2

Answer

Carbon dioxide

Question 20

The Krebs cycle takes place in which subcellular compartment?

Accepted Answer

Mitochondria

Answer

Cytoplasm

Answer

Nucleus

Answer

Endoplasmic reticulum

Question 21

Depletion of ATP in cells can lead to:

Accepted Answer

Inhibition of essential cellular functions

Answer

Increased metabolic activity

Answer

Enhanced DNA replication

Answer

Stimulation of protein degradation

Question 22

Which of the following processes is NOT directly involved in the generation of ATP in cells?

Accepted Answer

Transcription

Answer

Glycolysis

Answer

Krebs cycle

Answer

Oxidative phosphorylation

Question 23

Which molecule serves as the main energy currency of cells?

Accepted Answer

ATP

Answer

Glucose

Answer

NADH

Answer

FAD

Question 24

Which metabolic pathway is associated with the production of the highest number of ATP molecules per glucose molecule?

Accepted Answer

Oxidative phosphorylation

Answer

Glycolysis

Answer

Krebs cycle (citric acid cycle)

Question 25

Identify the process that represents an anabolic reaction.

Accepted Answer

Protein synthesis

Answer

Glycolysis

Answer

Oxidative phosphorylation

Answer

Cellular respiration