Question 1
What is the significance of glycolysis in anaerobic conditions?
A. It produces a large amount of ATP.
B. It converts pyruvate into acetyl CoA.
C. It allows for the production of a small net gain of ATP without oxygen.
D. It operates only in the presence of oxygen.
Question 2
What is the primary role of the Krebs cycle in cell respiration?
A. Producing glucose from pyruvate.
B. Oxidizing acetyl groups and producing reduced carriers (NADH and FADH2).
C. Creating a proton gradient in the mitochondrial cristae.
D. Converting glucose to pyruvate.
Question 3
How does the electron transport chain contribute to ATP synthesis?
A. By converting glucose to pyruvate.
B. By transferring electrons and pumping protons to create a proton gradient.
C. By directly synthesising ATP from ADP and inorganic phosphate.
D. By reducing oxygen to form water.
Question 4
Why is oxygen essential in the electron transport chain?
A. It acts as the final electron acceptor, maintaining the hydrogen gradient.
B. It directly participates in glycolysis.
C. It synthesises ATP.
D. It forms the proton gradient.
Question 5
What is the role of acetyl CoA in cell respiration?
A. It is the end product of glycolysis.
B. It enters the Krebs cycle for further oxidation.
C. It creates a proton gradient in the mitochondrial cristae.
D. It acts as the final electron acceptor in the electron transport chain.
Question 6
a) Explain the significance of glycolysis in anaerobic conditions and during energy demands. Why is it essential for cells? [3]
b) Describe the role of the Krebs cycle in oxidising acetyl groups and producing reduced carriers such as NADH and FADH2. [3]
Question 7
a) Discuss the process of chemiosmosis and how it leads to ATP synthesis using the proton gradient created in the mitochondrial cristae. [4]
b) Why is oxygen necessary to maintain the hydrogen gradient in the electron transport chain, and what is its role in water formation? [3]
Question 8
a) Describe the structure of the mitochondrion and explain how its adaptations are suited for cell respiration. [4]
b) How does the link reaction convert pyruvate into acetyl CoA, and why is this step crucial for entering the Krebs cycle? [3]
Question 9
a) Explain how glycolysis converts glucose to pyruvate and the conditions under which this process occurs. [3]
b) Discuss the role of the link reaction in converting pyruvate into acetyl CoA and its significance for the Krebs cycle. [4]
c) How does the electron transport chain contribute to creating a proton gradient in the mitochondrial cristae? [3]
Question 10
a) Discuss the importance of compartmentalisation in metabolic pathways and how it contributes to cellular efficiency. [4]
b) Describe the factors that affect enzyme activity and how they influence metabolic reactions. [3]
c) Explain the role of cofactors and coenzymes in assisting enzymatic reactions. Provide examples. [3]