What is the primary substrate for lipase in enzymatic actions?

Lipase is an enzyme that primarily acts on triglycerides, which are the main form of fat stored in the body. Triglycerides consist of a glycerol backbone attached to three fatty acid chains. When lipase catalyzes the hydrolysis of triglycerides, it breaks them down into glycerol and free fatty acids, which can then be used for energy or further metabolism.

This enzymatic action is crucial for the digestion of dietary fats, as it allows the body to convert the fats we consume into absorbable forms. In contrast, the other options, while related to lipid metabolism, do not serve as the primary substrate for lipase. Phospholipids are involved in membrane structure, cholesterol is integral to cellular membranes and hormone production, and fatty acids are products of triglyceride digestion rather than substrates for lipase activity.