What is the correct order for the following events that follow a nerve impulse along a sympathetic neuron to innervate the heart?
1) G protein activates adenylyl cyclase.
2) Neuron releases norepinephrine.
3) Cyclic AMP activates protein kinase.
4) Receptor activates G protein.
5) Protein kinase phosphorylates Ca²⁺ channels.
6) Receptors activated on the membrane of the cardiac muscle.

Question

Quizplus · Accepted Answer

The correct sequence starts with the neuron releasing norepinephrine (2), followed by the activation of receptors on the cardiac muscle (6). This leads to the activation of a G protein (4), which then activates adenylyl cyclase (1). The adenylyl cyclase converts ATP to cyclic AMP (cAMP), which activates protein kinase (3). Finally, the protein kinase phosphorylates channels (5), leading to the physiological effects on the heart.

What Is the Correct Order for the Following Events That