An enzyme acts as a catalyst during food manufacture.
How are collisions between the reactant particles affected by the enzyme?
The enzyme reacts with the particles in each collision, so the enzyme is used up.
More collisions happen each second because the enzyme pushes the particles closer together.
A larger fraction of collisions is successful because the minimum energy needed is lower.
Each successful collision releases more energy, so the overall energy change is larger.
127 exam-style questions on AQA GCSE Chemistry 6.1 Rate of reaction, covering 6.1.1a Calculating rates of reactions, 6.1.1b Gradient of a tangent as rate, 6.1.2 Factors which affect the rates of chemical reactions, 6.1.3 Collision theory and activation energy, and 6.1.4 Catalysts. Each one has a worked solution and a mark scheme showing where the marks go.