Final answer:
Cell responses mediated by Phospholipase C activation involve a signal molecule triggering the conversion of PIP₂ into IP3 and DAG, which serve as second messengers. DAG activates PKC leading to protein phosphorylation while IP3 induces Ca²⁺ release, together stimulating cellular responses such as gene expression, metabolism regulation, and cell growth or death.
Step-by-step explanation:
Cell responses mediated by Phospholipase C activation can be understood through a series of events in signal transduction. An effector signal molecule binds to its receptor on the cell surface, this triggers the activation of Phospholipase C, which then catalyzes the breakdown of phosphatidylinositol 4,5-bisphosphate (PIP₂) into Inositol triphosphate (IP3) and diacylglycerol (DAG). These serve as second messengers inside the cell.
DAG remains in the plasma membrane and activates Protein Kinase C (PKC), which subsequently phosphorylates proteins, altering their function and leading to various cellular responses. IP3, on the other hand, diffuses through the cytoplasm and binds to receptors on the smooth endoplasmic reticulum, resulting in the release of calcium ions (Ca²⁺) into the cytoplasm. The surge in Ca²⁺ levels, in conjunction with DAG, further stimulates PKC, setting in motion a cascade of phosphorylation events that lead to diverse cellular outcomes, such as gene expression, metabolism change, cell growth, or apoptosis.