[问答题]
Neuronal cells have special membrane properti
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4ohs 46efl8h rz /bxs8cell to another. The diagram below shows a portion of an axonal plasma membrane.
1.(1)State the role of a sodium-potassium pump in axon.
(2)Describe the action of the sodium-potassium pump.
2.Distinguish between simple diffusion, facilitated diffusion and active transport.
3.Compare and contrast sodium-potassium pumps and potassium channels.