Describe and explain how each of the following affects enzyme activity: pH, temperature.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2018). The mark or mark type is shown in brackets.

1. [7] (pH or temperature) best/optimum / fastest; rate slower both sides of the optimum ; active site; change in shape ; substrate no longer fits; shape of curve described ; denaturation + pH not optimum / high temperature AW ; (temperature only) Increase in temperature increases rate of reaction; heat increases rate of molecular movement / kinetic energy; more collisions (at higher temperature);
2. [3] named enzyme from alimentary canal ; correct named location for action of enzyme named ; correct named substrate + product(s) for substrate named ;