What is the correct order for the following events that follow a nerve impulse along a sympathetic neuron, and which innervates 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

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The correct sequence is: the neuron releases norepinephrine (2), which then activates receptors on the cardiac muscle membrane (6). This receptor activation leads to the activation of the G protein (4), which in turn activates adenylyl cyclase (1). Adenylyl cyclase converts ATP to cyclic AMP, which activates protein kinase (3). Finally, the protein kinase phosphorylates Ca²⁺ channels (5).

What Is the Correct Order for the Following Events That