Biology 9700/52 March 2018 | Cambridge AS Level Past Papers With Mark Scheme

1. Calculation of lipase concentrations in biological washing liquids, preparation of dilution series from a stock solution, and analysis of enzyme activity using pH changes.

2. Independent and dependent variables in enzyme concentration experiments, detailed experimental methods for assessing lipase activity using fat-stained fabric and pH probes.

3. Graphical representation of lipase concentration effects on fatty acid release rates, curve interpretation for determining ‘working’ concentrations, and evaluation of potential errors in results.

4. Investigation of critical flicker fusion threshold (CFFT) in humans, analysis of alcohol effects on sensory perception, and use of controlled variables to ensure experiment validity.

5. Importance of calculating standard deviation in sensory threshold experiments, identification of features from experimental data, and discussion of sample representativeness in population studies.