Final answer:
After dopamine binds to its G-protein-linked receptor, the concentration of cAMP (cyclic adenosine monophosphate) increases as a result of the activation of the enzyme adenylyl cyclase, converting ATP to cAMP. cAMP serves as a second messenger in cellular processes, facilitating varied physiological responses.
Step-by-step explanation:
Dopamine is a well-known neurotransmitter in the brain, playing a critical role in various neural processes, including reward, motivation, and motor control. When dopamine binds to its G-protein-linked receptor, a common pathway that is engaged involves the activation of an enzyme called adenylyl cyclase. This enzyme's role is to convert ATP (adenosine triphosphate) into cAMP (cyclic adenosine monophosphate).
The increase in cAMP concentrations is significant because cAMP acts as a second messenger within the cell, propagating the signal initiated by dopamine's binding to its receptor and leading to varied physiological responses. In the context of dopamine receptors, such as in the dopaminergic pathways in the brain, this signaling cascade can influence many functions ranging from mood regulation to learning and memory.
Therefore, the chemical expected to increase in concentration immediately after dopamine binds its receptor is b) cAMP. This is based on the knowledge that dopamine receptors are linked to the activation of adenylyl cyclase, as demonstrated in the beta-adrenergic receptors' response to hormones like epinephrine and norepinephrine, which share a similar mechanism with dopamine in signal transduction.