Question

Where are receptors for acetylcholine located?

Answer 1

Acetylcholine receptors (=cholinergic receptors) are present in plasma membrane, in fact the receptor is an integral membranar protein.

Explanation:

Acetylcholine is secreted at synaptic terminal of axon. Acetylcholine is a neurohumor substance and neurotransmitter.

Corresponding postsynaptic membrane must possess receptors for acetylcholine so that the neurosignal can be transmitted across the synapse.

Acetylcholine will trigger cholinergic receptors of nerve cell or muscle cell. The receptor molecule spans whole thickness of plasma memmbrane, hence has intracellular/cytoplasmic, extracellular and transmembranar domains.

Binding of acetylcholine on receptor molecule opens sodium ion entry gate across cell membrane.

There are two types of cholinergic receptors:

Nicotinic (also responds to nicotine),
and
Muscarinic (also responds to fungal toxin, muscarine).