starting with a signal reaching the distal end of the presyntatic axon, indicate correct order of events that occur during transmission at hte cholinergic excitatory synapse
1. opening of calcium gates in synaptic knob as nerve signal arrives
2. exocytosis of ACh; diffusion across synaptic cleft
3. binding of ACh to recptors on postsynaptic neuron
4. opening of sodium gates on post-synaptic membrane allowing influx of sodium
5. depolarization of postsynatpic plasma membrane