From that point, downward movement is described as acropetal (toward the apex). Movement of auxin from the apex of the root toward the root–shoot junction is also described as basipetal (toward the base).

TLS Online TPP Program

#Id: 5478

#Unit 7. System Physiology – Animal

TLS Online TPP Program

#Id: 5479

#Unit 7. System Physiology – Animal

Ca2+ uptake into the terminal causes release of the neurotransmitter acetylcholine (ACh), which has been previously synthesized and stored in synaptic vesicles.

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#Id: 5480

#Unit 7. System Physiology – Animal

ACh is formed from acetyl coenzyme A (acetyl CoA) and choline by the action of the enzyme choline acetyltransferase

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#Id: 5481

#Unit 7. System Physiology – Animal

ACh diffuses across the synaptic cleft to the postsynaptic Membrane of motor end plate, which contains nicotinic receptors

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#Id: 5482

#Unit 7. System Physiology – Animal

The nicotinic receptor for ACh is an example of a ligand-gated ion channel

TLS Online TPP Program

#Id: 5483

#Unit 7. System Physiology – Animal

ACh is degraded to choline and acetate by acetylcholinesterase (AChE) on the motor end plate