Cellular Respiration

Question 1

What is metabolic energy needed for?

Answer 1

Metabolic energy is required for cell growth, maintenance, repair, and reproduction.

Question 2

Why do animals need energy for movement?

Answer 2

Energy is needed for locomotion like running, flying, or swimming.

Question 3

What is the role of energy in maintaining body temperature?

Answer 3

Endotherms use energy to maintain a constant body temperature for optimal physiological processes.

Question 4

How does energy support reproduction?

Answer 4

Reproduction, including gamete production and offspring care, requires significant energy investment.

Question 5

What is the energy used for in foraging and hunting?

Answer 5

Herbivores use energy to find and digest plants; carnivores use it to hunt and process prey.

Question 6

What is photosynthesis?

Answer 6

Photosynthesis is the process where autotrophic organisms use sunlight to create glucose from CO2 and H2O.

Question 7

Why are chemical reactions important in cells?

Answer 7

Cells require energy for biochemical processes like protein synthesis and active transport.

Question 8

How do extremophiles use energy?

Answer 8

Extremophiles use energy to adapt to extreme environments like high radiation or temperature.

Question 9

What is the energy currency in all living things?

Answer 9

ATP (adenosine triphosphate).

Question 10

What does ATP stand for, and what is its role in the cell?

Answer 10

ATP stands for adenosine triphosphate, and it stores and transfers energy for cellular processes.

Question 11

Name three cellular processes that use ATP.

Answer 11

Active transport, macromolecule synthesis (anabolism), and muscle contraction.

Question 12

What molecules control the process of respiration?

Answer 12

Enzymes control the process of cellular respiration.

Question 13

What are the products of aerobic respiration?

Answer 13

A: Carbon dioxide (CO2) and water (H2O), with ATP as the energy product.

Question 14

How does anaerobic respiration differ from aerobic respiration?

Answer 14

Anaerobic respiration occurs without oxygen and produces less ATP (2 ATP) compared to aerobic (36-38 ATP).

Question 15

Why is anaerobic respiration important for humans?

Answer 15

It provides rapid energy during intense activity and ensures survival when oxygen is limited.

Question 16

What are two examples of organic molecules used in respiration besides glucose?

Answer 16

Fatty acids and amino acids.

Question 17

How does glycolysis function in cellular respiration?

Answer 17

Glycolysis breaks down glucose into pyruvate in the cytoplasm, producing ATP and NADH.

Question 18

What is the role of NAD+ in glycolysis?

Answer 18

NAD+ accepts electrons during the oxidation of G3P, becoming NADH.

Question 19

What happens to ATP during glycolysis?

Answer 19

Two ATP are consumed to activate glucose, and four ATP are produced, resulting in a net gain of two ATP.

Question 20

What happens to pyruvate after glycolysis?

Answer 20

Pyruvate can enter the citric acid cycle or undergo fermentation if oxygen is absent.

Question 21

What is the role of NADH in cellular respiration?

Answer 21

NADH carries high-energy electrons to later stages of cellular respiration to produce ATP.

Question 22

What is the main advantage of aerobic respiration over anaerobic respiration?

Answer 22

Aerobic respiration produces a larger yield of ATP (36-38 ATP).

Question 23

What are the four main stages of glycolysis?

Answer 23

Phosphorylation, lysis, oxidation, and ATP formation.

Question 24

What role does the cytoplasm play in glycolysis?

Answer 24

The cytoplasm provides the environment for the glycolytic enzymes to carry out reactions.

Question 25

How does temperature affect the rate of respiration in organisms?

Answer 25

Lower temperatures decrease the rate of respiration by slowing down metabolic reactions.

Question 26

Why is it crucial to regenerate NAD in anaerobic respiration?

Answer 26

Regenerating NAD allows glycolysis to continue by providing NAD+ as an electron carrier.

Question 27

What is the purpose of converting pyruvate to lactate in anaerobic respiration?

Answer 27

To regenerate NAD+ from NADH, enabling glycolysis to continue and produce ATP.

Question 28

How and why is yeast used in bread making?

Answer 28

Yeast ferments sugars to produce CO2, which causes the dough to rise and create a light, airy texture.

Question 29

How does yeast fermentation contribute to bread making?

Answer 29

Fermentation creates CO2 for leavening, develops flavors, and preserves bread.

Question 30

What is bioethanol and how is it produced using yeast?

Answer 30

Bioethanol is ethanol produced by yeast fermenting plant sugars, followed by distillation and dehydration.

Question 31

How does anaerobic respiration differ in humans and yeasts?

Answer 31

Humans use lactic acid fermentation, while yeasts use alcoholic fermentation to produce ethanol.

Question 32

What is the role of Coenzyme A in the transition reaction?

Answer 32

Coenzyme A combines with pyruvate to form acetyl-CoA, which enters the citric acid cycle.

Question 33

What is the role of acetyl-CoA in the transition reaction?

Answer 33

Acetyl-CoA carries a two-carbon acetyl group into the citric acid cycle.

Question 34

What is the role of carbon dioxide in the transition reaction?

Answer 34

CO2 is released when one carbon from pyruvate is removed, forming acetyl-CoA.

Question 35

What does oxaloacetate do in the citric acid cycle?

Answer 35

Oxaloacetate combines with acetyl-CoA to form citrate, starting the cycle.

Question 36

What is citrate’s role in the citric acid cycle?

Answer 36

Citrate undergoes transformations, producing NADH, FADH2, and regenerating oxaloacetate.

Question 37

What is acetyl-CoA’s function in the citric acid cycle?

Answer 37

Acetyl-CoA delivers the acetyl group to initiate the citric acid cycle.

Question 38

What role does CO2 play in the citric acid cycle?

Answer 38

CO2 is released as a by-product during decarboxylation steps in the cycle.

Question 39

What is NADH’s role in the citric acid cycle?

Answer 39

NADH carries electrons to the electron transport chain for ATP production.

Question 40

What is FADH2’s role in the citric acid cycle?

Answer 40

FADH2 carries electrons to the electron transport chain, aiding ATP production.

Question 41

How is ATP produced in the citric acid cycle?

Answer 41

ATP is generated through substrate-level phosphorylation during the cycle.

Question 42

How is NAD+ regenerated in the electron transport chain?

Answer 42

NADH donates electrons to the ETC, regenerating NAD+ for reuse in cellular respiration.

Question 43

How does the ETC pump protons across the inner mitochondrial membrane?

Answer 43

Energy released by electrons moving through the ETC pumps protons into the intermembrane space.

Question 44

What happens if the ETC is blocked?

Answer 44

Blocking the ETC prevents NAD+ regeneration and halts ATP production, causing energy depletion.

Question 45

How could you test if NADH oxidation drives the electron transport chain?

Answer 45

By monitoring oxygen consumption and proton movement in isolated mitochondria with varying NADH levels.

Question 46

What is the function of an electron donor in the electron transport chain?

Answer 46

An electron donor, like NADH or FADH2, provides high-energy electrons to the ETC.

Question 47

What does Complex I do in the electron transport chain?

Answer 47

Complex I transfers electrons from NADH to ubiquinone, pumping protons across the membrane.

Question 48

What does Complex II do in the electron transport chain?

Answer 48

Complex II transfers electrons from FADH2 to ubiquinone without pumping protons.

Question 49

What does Complex III do in the electron transport chain?

Answer 49

Complex III transfers electrons to cytochrome c while pumping protons across the membrane.

Question 50

What does Complex IV do in the electron transport chain?

Answer 50

Complex IV transfers electrons to oxygen, producing water and pumping protons across the membrane.

Question 51

What is the function of oxygen in the electron transport chain?

Answer 51

Oxygen accepts electrons from Complex IV, forming water and allowing continued electron flow.

Question 52

How does the proton gradient help ATP synthesis?

Answer 52

The proton gradient stores potential energy, which is used by ATP synthase to produce ATP.

Question 53

What is ATP synthase’s role in the electron transport chain?

Answer 53

ATP synthase uses the energy from the proton gradient to synthesize ATP.

Question 54

How can you test the chemiosmotic theory of ATP production?

Answer 54

By measuring ATP production, proton gradient, and proton movement in mitochondria under various conditions.

Question 55

How is ATP produced without glucose in cellular respiration?

Answer 55

ATP can be produced by bypassing glycolysis and using alternative substrates directly in the citric acid cycle.