lipid catabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the breakdown of lipids, compounds soluble in an organic solvent but not, or sparingly, in an aqueous solvent. [GOC:go_curators]

Lipid catabolic processes encompass a series of biochemical reactions that break down complex lipid molecules into simpler units, releasing energy and generating building blocks for other metabolic processes. These processes are essential for various cellular functions, including energy production, membrane remodeling, and signaling. The breakdown of lipids typically occurs in three main stages:

1. **Hydrolysis:** Lipases, a group of enzymes, catalyze the breakdown of triacylglycerols (fats) into glycerol and free fatty acids. This step involves the addition of water molecules, breaking the ester bonds that link fatty acids to glycerol.

2. **β-Oxidation:** Fatty acids undergo β-oxidation in the mitochondria, a process that involves a series of four enzymatic reactions. Each cycle of β-oxidation removes two carbon atoms from the fatty acid chain in the form of acetyl-CoA, a key molecule in cellular energy production. The process continues until the entire fatty acid is broken down into acetyl-CoA molecules.

3. **Acetyl-CoA Metabolism:** The acetyl-CoA generated from β-oxidation enters the citric acid cycle (Krebs cycle), a central pathway in cellular respiration, where it is further oxidized to generate ATP, the primary energy currency of cells.

In addition to triacylglycerols, other lipids, such as phospholipids and cholesterol, are also subjected to catabolic processes. The breakdown of phospholipids involves the removal of the phosphate group and the hydrolysis of the ester bonds connecting fatty acids to glycerol. Cholesterol catabolism involves the conversion of cholesterol into bile acids, which aid in fat digestion and absorption in the intestines.

Lipid catabolic processes are tightly regulated by various factors, including hormones, cellular energy levels, and nutrient availability. These processes play a vital role in maintaining cellular homeostasis, energy production, and overall organismal health. Dysregulation of lipid catabolism can contribute to various metabolic disorders, including obesity, diabetes, and cardiovascular diseases.'
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Proteins (19)

Compounds (252)