glycerol catabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the breakdown of glycerol, 1,2,3-propanetriol, a sweet, hygroscopic, viscous liquid, widely distributed in nature as a constituent of many lipids. [GOC:go_curators, ISBN:0198506732]

Glycerol catabolism is the breakdown of glycerol, a three-carbon alcohol, into smaller molecules that can be used for energy production. This process occurs in various organisms, including bacteria, fungi, and animals. Here's a detailed description of the process:

**1. Activation of glycerol:**

* Glycerol enters the cell and is phosphorylated by glycerol kinase, using ATP, to form glycerol-3-phosphate.

**2. Oxidation of glycerol-3-phosphate:**

* Glycerol-3-phosphate dehydrogenase, an enzyme located in the mitochondrial membrane, oxidizes glycerol-3-phosphate to dihydroxyacetone phosphate (DHAP), using NAD+ as the electron acceptor. This reaction is coupled to the reduction of NAD+ to NADH.

**3. Entry into glycolysis:**

* DHAP is a key intermediate in glycolysis, the main pathway for glucose breakdown. It can either directly enter glycolysis or be converted to glyceraldehyde-3-phosphate (GAP) by triose phosphate isomerase.

**4. Further metabolism:**

* Once DHAP or GAP enters glycolysis, it undergoes a series of reactions to produce pyruvate, which is then further metabolized in the citric acid cycle and oxidative phosphorylation to generate ATP.

**Metabolic Significance:**

* **Energy production:** Glycerol catabolism contributes to cellular energy production by generating NADH and ATP.
* **Utilization of alternative substrates:** It allows organisms to utilize glycerol as a carbon source and energy source when other substrates, such as glucose, are limited.
* **Metabolic regulation:** The enzymes involved in glycerol catabolism are subject to regulation, ensuring efficient utilization of glycerol based on the cell's energy needs.

**Examples:**

* In bacteria, glycerol catabolism plays a crucial role in their metabolism, especially when they are growing on substrates containing glycerol.
* In mammals, glycerol is a byproduct of fat metabolism, and its catabolism contributes to energy production.

**Overall, glycerol catabolism is a vital process that enables organisms to utilize glycerol as a source of energy and carbon, contributing to their overall metabolic flexibility.**'
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Proteins (1)

Compounds (2)