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Enzymes and digestion

6 lessons in Organisation.

40 exam questions · 88 marks

2.2 Enzymes and the lock and key model What enzymes are, how the shape of the active site makes each enzyme specific to one substrate, the lock and key model, and what happens when an enzyme is denatured. AQA Edexcel OCR 2.3 Factors affecting enzyme activity How temperature, pH, substrate concentration and enzyme concentration change the rate of an enzyme-controlled reaction, what an optimum is, and how to calculate a rate of reaction. AQA Edexcel OCR 2.4 Required practical: pH and amylase The required practical for the effect of pH on amylase: the starch and iodine continuous sampling method, variables, how to calculate rate as 1000 divided by time, and how to make the results more accurate. AQA Edexcel OCR 2.5 The digestive system and digestive enzymes The organs of the digestive system, the three groups of digestive enzymes (carbohydrases, proteases and lipases), where they are made and what they produce, and how bile helps digestion. AQA Edexcel OCR 2.6 Required practical: food tests How to test foods for starch, reducing sugars, protein and lipids using iodine, Benedict's solution, biuret reagent and Sudan III or the ethanol emulsion test, with the colour changes, safety and how to prepare a food sample. AQA Edexcel OCR 2.7 Measuring the energy in food (calorimetry) Edexcel core practical: burning a food sample under a boiling tube of water to measure the energy it contains, calculating energy with mass of water x 4.2 x temperature rise, and why the result is lower than the true value. Separate only Edexcel