Nervous coordination (A-level only)

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Question 10

Medium

Figure 1 shows a schematic diagram of a synapse during transmission.

Schematic diagram of a synapse showing a presynaptic terminal, synaptic cleft, and postsynaptic membrane. Label A points to a channel on the presynaptic membrane. Label B points to a vesicle fusing with the presynaptic membrane. Label C points to the synaptic cleft. Label D points to a channel on the postsynaptic membrane.

Name the structures or spaces labelled A to D to identify the key components involved in synaptic transmission shown in Figure 1.

[2]

The arrival of an action potential at the presynaptic knob leads to the release of neurotransmitter. Describe the sequence of events, starting from the depolarisation of the presynaptic membrane, that results in the release of neurotransmitter into the synaptic cleft.

[4]

Certain snake venoms contain neurotoxins that act as competitive antagonists by binding to the postsynaptic receptors (labelled D), preventing acetylcholine from binding. Explain how these neurotoxins prevent the transmission of action potentials.

[2]

Nervous coordination (A-level only)

Question 10

Nervous coordination (A-level only) Questions

Nervous coordination (A-level only)

Question 10

Nervous coordination (A-level only) Questions