IB Biology HL C1.1.8 Effects on Enzyme Activity Questions

Explore how temperature, pH and substrate concentration affect enzyme activity, from the optimum temperature and active-site bonding to saturation in IB Biology HL C1.1.8.

Exam points

Explain how increasing temperature raises enzyme activity to an optimum, after which denaturation lowers the rate.
Explain how pH changes alter bonding at the enzyme active site and affect enzyme activity.
Interpret substrate-concentration data to explain the rise in enzyme activity to a saturation plateau.

[Maximum number: 3]

Cholinergic synapses use acetylcholine as their neurotransmitter. They are widespread in the body, passing on signals to muscle cells. These synapses are affected by neonicotinoid pesticides.

The diagrams, which are not drawn to scale, show the synapse between two neurons and a detail of the synaptic cleft.

Figure for Question IB Biology HL C1.1.8 Effects on Enzyme Activity Questions question 1 — IB Biology HL

Explain what happens to an enzyme if there is a change of pH .

a. change in pH can cause a change in the tertiary structure of the enzyme OR enzyme denatured
b. causing a change in the active site / substrate not able to bind $\boldsymbol{}$
c. the enzyme will not work as efficiently / decreased rate of reaction
d. (may no longer be) the optimum/optimal pH for enzyme activity

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IB Biology HL C1.1.8 Effects on Enzyme Activity Questions question 1