Exam-Style Questions
1. The bar chart shows the sources of energy for 1 hour of cycling.
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 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 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.
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 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)