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How does phospholipase C produce diacylglycerol and triphosphoinositol?

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A composite diagram shows the structural formulas, space-filling models, and simplified depictions of lipid molecules including stearic acid and phosphatidylcholine, and how these assemble into a micelle and lipid bilayer, with labels identifying hydrophilic heads and hydrophobic tails. — Lipid Structure and properties of two representative lipids. Both stearic acid (a fatty acid) and phosphatidylcholine (a phospholipid) are composed of chemical groups that form polar “heads” and nonpolar “tails.” The polar heads are hydrophilic, or soluble in water, whereas the nonpolar tails are hydrophobic, or insoluble in water. Lipid molecules of this composition spontaneously form aggregate structures such as micelles and lipid bilayers, with their hydrophilic ends oriented toward the watery medium and their hydrophobic ends shielded from the water.

Phospholipase C produces diacylglycerol and triphosphoinositol through the hydrolysis of a specific membrane phospholipid called phosphatidylinositol bisphosphate.1

When a cell membrane receptor is activated by an external signal, it triggers the enzyme phospholipase C, which is located on the inner surface of the membrane. This enzyme then catalyzes the hydrolysis of phosphatidylinositol bisphosphate, resulting in two distinct second-messenger molecules:1

Diacylglycerol (diglyceride): This molecule remains within the membrane bilayer, where it activates protein kinase C.1
Triphosphoinositol: This product is released and functions to trigger the release of calcium from intracellular stores.1

Together, these components form a critical intracellular second-messenger signaling system that allows cells to respond to various physiological stimuli.1