8.1 Metabolism

Which statement best describes the role of ATP in metabolic reactions?

A. ATP acts only in catabolic reactions.

B. ATP provides structural support to enzymes.

C. ATP supplies energy to drive endergonic reactions.

D. ATP is only used in carbohydrate metabolism.

How does enzyme specificity contribute to metabolic pathways?

A. It allows any substrate to bind to the enzyme.

B. It ensures that each enzyme catalyses multiple reactions.

C. It ensures the correct sequence of reactions by binding specific substrates.

D. It prevents the binding of cofactors and coenzymes.

What is the significance of compartmentalisation in metabolic pathways?

A. It decreases the efficiency of metabolic reactions.

B. It allows for simultaneous anabolic and catabolic reactions.

C. It prevents the synthesis of ATP.

D. It reduces the specificity of enzymes.

Which statement about the first and second laws of thermodynamics in biochemical reactions is correct?

A. The first law states that energy is lost as heat in every energy transfer.

B. The second law states that the total energy in a closed system remains constant.

C. The first law states that energy can be created and destroyed.

D. The second law states that every energy transfer increases the entropy of the universe.

How does feedback inhibition maintain metabolic homeostasis?

A. It increases the production of end products.

B. It prevents the use of intermediates in other pathways.

C. It accelerates the rate of enzyme activity.

D. The end product inhibits an earlier enzyme, regulating the pathway.

a) Explain how metabolic pathways can be both anabolic and catabolic, providing one example for each. [4]

b) Discuss the importance of compartmentalisation in metabolic pathways. [3]

a) Describe the nature of enzyme catalysis and the significance of the active site in enzymatic reactions. [3]

b) How do cofactors and coenzymes assist enzymatic reactions? Provide an example. [4]

a) Discuss the first and second laws of thermodynamics in the context of energy changes in biochemical reactions. [4]

b) Explain the role of ATP as the energy currency of the cell and how it is synthesised. [3]

a) Describe the role of intermediates in metabolic pathways and explain why they are important. [3]

b) How does end-product inhibition contribute to metabolic homeostasis? Provide an example. [4]

c) Discuss the factors that affect enzyme activity and how they influence metabolic reactions. [4]

a) Explain the concept of anabolic and catabolic pathways and how they are interconnected. [3]

b) Discuss the significance of compartmentalisation in maintaining the efficiency of metabolic pathways. [4]

c) How do the first and second laws of thermodynamics apply to the energy changes observed in cellular metabolism? [4]