Explain how neurons communicate across a synapse.

  1. A neuronal action potential depolarises the pre-synaptic membrane (neuron 1) causing voltage-gated calcium channels to open.2) Extracellular calcium ions bind to receptors on the pre-synaptic membrane causing vesicles containing a neurotransmitter to move towards the membrane in the process of exocytosis.3) The vesicles fuse with the membrane and the neurotransitters are deposited in the synaptic cleft.4) The neurotransmitter molecules diffuse across the synaptic cleft and bind to their complimentary receptors on the post-synaptic membrane (neuron 2).5) Sodium ion channels on the post-synaptic membrane open, causing the membrane to depolarise and initiating an action potential down the neuronal membrane.

Related Biology A Level answers

All answers ▸

Why is ATP used as an energy store in cells?


Starting with mRNa in the cytoplasm, describe how translation leads to the production of a polypeptide ( without including transcription or slicing)


How would blood glucose levels be lowered upon becoming too high?


Describe the structure of DNA in the eukaryotic cell