2.1.4 ENZYMES

Question 1

the role of enzymes in catalysing reactions
that affect metabolism at a cellular and whole
organism level
To include the idea that enzymes affect both
structure and function.

Question 2

the role of enzymes in catalysing both
intracellular and extracellular reactions
To include catalase as an example of an enzyme that
catalyses intracellular reactions and amylase as an
example of an enzyme that catalyses extracellular
reactions.

Question 3

the mechanism of enzyme action To include the tertiary structure, specificity,
active site, lock and key hypothesis, induced-fit
hypothesis, enzyme-substrate complex, enzymeproduct complex, product formation and lowering of activation energy / providing an alernate reaction pathway.

Question 4

(d) (i) the effects of pH, temperature, enzyme
concentration and substrate concentration
on enzyme activity
(ii) practical investigations into the effects of
pH, temperature, enzyme concentration and
substrate concentration on enzyme activity
To include reference to the temperature coefficient
(Q10).
Q10=R2/R1

Question 5

PAG4:

The effect of substrate concentration
on the rate of an enzyme controlled
reaction

Use of appropriate apparatus to record a range of
quantitative measurements (to include mass, time,
volume, temperature, length and pH)3
* Use of laboratory glassware apparatus for a variety of
experimental techniques to include serial dilutions4
* Use of ICT such as computer modelling, or data logger
to collect data, or use of software to process data 5

Question 6

the need for coenzymes and cofactors in some
enzyme-controlled reactions
To include the chloride ion as a cofactor for amylase
and vitamins as a source of coenzymes.

Question 7

(f) the effects of inhibitors on the rate of enzymecontrolled reactions.
To include competitive and non-competitive,
reversible and non-reversible inhibitors, and the role
of end-product inhibition.