Which observation best indicates that an enzyme used in alcoholic-drink production is acting as a catalyst?
It increases the mass of sugar available to react
It becomes part of the ethanol product as it reacts
It speeds the conversion but is not consumed overall
It supplies carbon atoms to the alcohol molecules
54 exam-style questions on Edexcel GCSE Chemistry 8.1 Rates of reaction, covering 8.1.1 Measuring and interpreting rates of reaction, 8.1.2 Collision theory and the factors affecting rate, and 8.1.3 Catalysts and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.