Final answer:
Lipolysis is the process where triglycerides are hydrolyzed into free fatty acids and glycerol, which are then used to produce energy through β-oxidation and the Krebs cycle, primarily when glucose is scarce.
Step-by-step explanation:
Lipolysis is the breakdown of lipids, which involves the hydrolysis of triglycerides into free fatty acids. These free fatty acids can undergo degradation through a process known as β-oxidation to produce energy for the body. This energy production is especially important when glucose levels are low, such as during fasting or heavy exercise. During lipolysis, triglycerides stored in adipose tissue are broken down into glycerol and free fatty acids by the enzyme 'hormone-sensitive lipase'. The glycerol can then enter the glycolysis pathway as DHAP, and the fatty acids are transported to various tissues to be oxidized into acetyl CoA. Acetyl CoA enters the Krebs cycle, generating ATP through aerobic respiration. Triglycerides yield more than twice the energy per unit mass compared to carbohydrates and proteins, making fat an essential energy reservoir.