What is the Origin of Fat Catabolism?

The term combines 'fat,' referring to lipids or adipose tissue, and 'catabolism,' derived from the Greek katabole, meaning a "throwing down," which in biochemistry signifies the breaking down of complex molecules into simpler ones. This concept is central to the field of metabolism, defining the energy-releasing phase of biochemical reactions. The understanding of this pathway emerged with the elucidation of beta-oxidation in the early 20th century.

What is the Mechanism of Fat Catabolism?

Hormones such as glucagon, epinephrine, and cortisol activate hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) within adipocytes. These enzymes catalyze the hydrolysis of triglycerides into fatty acids and glycerol. The released fatty acids are then transported via the bloodstream, often bound to albumin, to tissues like muscle and liver, where they enter the mitochondria for beta-oxidation, yielding acetyl-CoA for the Krebs cycle and ATP generation.

Fat Catabolism ∞ Area

Fat Catabolism

Meaning

The metabolic pathway involving the breakdown of stored triglycerides, primarily within adipose tissue, into free fatty acids and glycerol, which are subsequently utilized by other tissues for energy production. This process, also known as lipolysis, is a critical component of energy homeostasis, especially during periods of fasting or prolonged physical activity. Effective fat catabolism is vital for maintaining a healthy body composition and metabolic flexibility.