Cambridge AS & A Level Biology

12.2Respiration

Respiration in Cambridge AS & A Level Biology: what the syllabus expects you to know, the learning objectives and how to practise.

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Learning objectives

What the syllabus expects you to be able to do.

12.2.1State the sites of glycolysis, the link reaction, the Krebs cycle and oxidative phosphorylation.
12.2.2Outline glycolysis: phosphorylation of glucose, splitting of fructose 1,6-bisphosphate into triose phosphates and oxidation to pyruvate with ATP and reduced NAD.
12.2.3Explain that pyruvate enters mitochondria for the link reaction when oxygen is available.
12.2.4Describe the link reaction, including the role of coenzyme A.
12.2.5Outline the Krebs cycle from oxaloacetate and acetyl CoA to citrate and back.
12.2.6Explain decarboxylation, dehydrogenation and the reduction of NAD and FAD in the Krebs cycle.
12.2.7Describe how NAD and FAD carry hydrogen to the inner mitochondrial membrane.
12.2.8Explain oxidative phosphorylation: electron transport, proton pumping, chemiosmosis through ATP synthase and oxygen as final electron acceptor.
12.2.9Relate the structure of mitochondria to their function.
12.2.10Outline lactate fermentation in mammals and ethanol fermentation in yeast.
12.2.11Explain why aerobic respiration yields much more energy than anaerobic respiration.
12.2.12Explain how rice is adapted to grow with submerged roots.
12.2.13Use redox indicators (DCPIP, methylene blue) to investigate the effects of temperature and substrate concentration on yeast respiration.
12.2.14Use simple respirometers to investigate the effect of temperature on respiration rate.

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