Biology · Oct / Nov 2025 · Paper 42 · Question 3

increases the rate of a (chemical) reaction ;

(and is) not changed (during the reaction) / AW ;

any six from:

1

amylase breaks down starch ;

2

iodine (solution) turns blue-black in the presence of starch ;

idea that at 0 °C / at the start

3

least, starch break down / enzyme activity / amylase activity ;

4

fewest, successful collisions / enzyme substrate-complexes formed ; 5

idea that particles do not have sufficient (kinetic)

energy ;

idea as temperature increases

6

the kinetic energy (of particles) increases ;

7

(starch and amylase) collide more, frequently / successfully or more enzyme-substrate complexes form ;

8

faster break down of starch ;

9

40 °C is the optimum temperature ;

any two from:

ref to specificity ;

idea that protease has a different shaped active site (to amylase) / starch and the active site (of protease) are not complementary ;

unable to bind / unable to form an enzyme-substrate complex ;

pH / AVP ;