Chapter 18 (Respiration)

Question 1

What are the stages of aerobic respiration?

Answer 1

1) glycolysis
2) link reaction
3) Krebs cycle
4) electron transport chain

Question 2

What are the main stages of glycolysis?

Answer 2

1) Phosphorylation- 2 ATP molecules transfer 1 phosphate each to glucose, forming hexose bisphosphate
2) Lysis- Hexose bisphosphate is destabilised, splitting into 2 triose phosphate molecules
3) Phosphorylation- 1 free inorganic phosphate attaches to each triose phosphate, forming triose bisphosphate
4) Dehydrogenation and formation of ATP- Per triose bisphosphate, one hydrogen atom is removed to reduce NAD and two phosphates are removed to form ATP from ADP

In total, 2 molecules of ATP (4 - 2 used to prime the reaction) and 2 reduced NAD are produced.

Question 3

What are the respiratory quotient (RQ) values for common substrates?

Answer 3

Carbohydrates= 1.0
Protein= 0.9
Lipids= 0.7

Question 4

How is RQ calculated?

Answer 4

RQ= CO2 produced/O2 consumed

Question 5

What are the stages of the Krebs cycle?

Answer 5

1) Oxaloacetate (4C) combines with an acetyl group to form citrate (6C)
2) Decarboxylation + Dehydrogenation, produces 5C compound
3) Decarboxylation+ Dehydrogenation, produces 4C compound
4) ATP, FADH2 and reduced NAD formed, regenerating oxaloacetate