G protein‑coupled receptors (GPCRs) transform external stimuli to intracellular signals. The G protein associated with the receptor is activated by ligand binding, regulating an enzyme that produces a second messenger. The second messenger, in turn, brings about changes within the cell. Components of two common second messenger pathways are given. Identify the next component of each signaling pathway. Each compound or ion may be used once or more than once. One target requires two answers. The given abbreviations are used: cAMP, cyclic AMP; DAG, diacylglycerol; IP3, inositol triphosphate; PIP2, phosphatidylinositol 4,5‑bisphosphate; PKA, protein kinase A (cAMP‑dependent protein kinase); PKC, protein kinase C; PLC, phospholipase C.

The question lacks the correct table format. The correct table has been attached below.

The G protein‑coupled receptors are used for the signaling cascade for the transmission of cell signaling and cell communication. These receptors require primary messengers as well as secondary messenger.  

The primary messenger activates the secondary messenger that activates the signaling in the cell. IP3 requires Calcium as secondary messenger, PIP2, phosphatidylinositol 4,5-bisphosphate and  PLC, phospholipase C requires  IP3 and DAG ( diacylglycerol) as signaling molecule. cyclic AMP requires Protein kinase A and calcium requires protein kinase C. ATP and adenylyl cyclase has cAMP as secondary messenger and DAG requires PKC as secondary molecules.

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