Using acetylcholine as an example, explain how the same signal molecule can induce different responses in different target cells.
A.
Different cell types are configured to respond to the neurotransmitter acetylcholine in different ways.
B.
When a heart pacemaker cell is exposed to the neurotransmitter acetylcholine, its rate of firing decreases.
C.
When a salivary gland cell is exposed to the same signal, it secretes components of saliva, even though the receptors on both cell types are the same.
D.
In skeletal muscle, acetylcholine binds to a different receptor protein, causing the muscle cell to contract.