Exam-Style Questions: Respiration

1. The bar chart shows the sources of energy for 1 hour of cycling.

Exam style questions

a) What percentage of the energy came from carbohydrates?

b) Glycogenolysis and gluconeogenesis both contribute to the formation of respiratory substrates during exercise.

What is meant by:

(i) Glycogenolysis?

(ii) Gluconeogenesis?

(Marks available: 3)

Answer

 

Answer outline and marking scheme for question: 1

Give yourself marks for mentioning any of the points below:

a) 57

(1 mark)

b) (i) Breakdown of glycogen to glucose

(ii) Breakdown of lipids/protein to respiratory substrates/sugars carbohydrate/glucose.

(2 marks)

(Marks available: 3)

 

2. a) What part do the following coenzymes play in respiration?

(i) NAD

(ii) Coenzyme A

b) NAD is made from the vitamin niacin. Niacin is required only in small quantities in the human diet. Explain why?

(Marks available: 5)

Answer

 

Answer outline and marking scheme for question: 2

Give yourself marks for mentioning any of the points below:

a) (i) Hydrogen acceptor carrier; role in oxidative phosphorylation/Krebs cycle/glycolysis/electron transfer.

(ii) Transfers acetyl compound/C2 to C4 acceptor; into mitochondrion/Krebs cycle.

(4 marks)

b) Reference to reuse/recycling of coenzymes.

(1 mark)

(Marks available: 5)

 

3. The diagram shows chemical pathways involved in respiration and photosynthesis.

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a) Name the process that produces pyruvate from glucose.

b) Name the compounds labled X and Y.

c) (i) In which part of the chloroplast is glycerate 3-phosphate converted into ribulose biphosphate?

(ii) Describe the role of ribulose biphosphate in photosynthesis.

(Marks available: 5)

Answer

 

Answer outline and marking scheme for question: 3

Give yourself marks for mentioning any of the points below:

a) Glycolysis/oxidation

(1 mark)

b) Reduced NAD/NADH; ATP

(2 marks)

c) (i) Stroma

(ii) Combines with/accepts carbon dioxide

(2 marks)

(Marks available: 5)