Paper 2 2021 Questions

Question 1

Describe the process of glycolysis

Answer 1

— Phosphorylation of glucose using ATP
— Oxidation of triode phosphate to pyruvate
— Net gain of ATP
— NAD reduced

Question 2

Malonate inhibits a reaction in the kerbs cycle
Explain why malonate would decrease the uptake of oxygen in a respiring cell?

Answer 2

— Less/no reduced NAD/ coenzymes
— oxygen is the final electron acceptor

Question 3

Explain how a resting potential is maintained across the axon membrane in a neurone?

Answer 3

— Higher concentration of potassium ions inside and higher concentration of sodium ions outside the neurone
— membrane more permeable to potassium ions
— sodium ions actively transported out and potassium ions in

Question 4

Explain why the speed of transmission of impulses is faster along a myelinated£ axon than along a non-myelinated axon than along a non-myelinated axon?

Answer 4

— In myelinated salatory conducatipn
— Myelination provides electrical insulation
— Non-myelinated depolarisation occurs along the whole length of the axon