When a nerve impulse arrives at a synapse, it causes the release of neurotransmitter from vesicles in the presynaptic knob. Describe how.
The arrival of a nerve impulse at a synapse causes Ca2+ channels to open (1 mark). Ca2+ ions enter the presynaptic knob by facilitated diffusion (1 mark). The presence of Ca2+ ions causes synaptic vesicles to fuse with the presynaptic membrane and the subsequent release of neurotransmitter into the synapse (1 mark).
AB
Related Biology A Level answers
All answers ▸State 3 organelles found in a Eukaryotic cell and the functions of each organelle.
Describe the process of synaptic transmission at the neuromuscular junction.
Explain what 'water potential' is, and how it relates to bacterial cell death. (3 marks)
Explain the differences between neuronal and hormonal communication and give an example of each.