pyruvate catabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the breakdown of pyruvate, 2-oxopropanoate. [GOC:go_curators]

Pyruvate catabolic process is a fundamental metabolic pathway that plays a pivotal role in energy production in living organisms. It involves the breakdown of pyruvate, a three-carbon molecule, to generate ATP (adenosine triphosphate), the primary energy currency of cells. This process occurs in the mitochondria, the powerhouses of cells, and can be divided into three main stages:

1. **Glycolysis:** This initial stage occurs in the cytoplasm and involves the breakdown of glucose into two molecules of pyruvate. During glycolysis, two molecules of ATP and two molecules of NADH (nicotinamide adenine dinucleotide) are produced.

2. **Pyruvate oxidation:** In this stage, pyruvate is transported from the cytoplasm into the mitochondrial matrix, where it is decarboxylated (loses a carbon dioxide molecule) to form acetyl-CoA (acetyl coenzyme A). This reaction is catalyzed by the enzyme pyruvate dehydrogenase complex, which requires several coenzymes, including thiamine pyrophosphate (TPP), lipoic acid, NAD+, and Coenzyme A.

3. **Krebs cycle (also known as the citric acid cycle):** Acetyl-CoA enters the Krebs cycle, a series of eight enzymatic reactions that generate ATP, NADH, and FADH2 (flavin adenine dinucleotide). The carbon atoms from acetyl-CoA are oxidized to carbon dioxide, and the energy released is used to generate ATP and electron carriers.

The NADH and FADH2 produced in both pyruvate oxidation and the Krebs cycle carry electrons to the electron transport chain, a series of protein complexes embedded in the mitochondrial inner membrane. This chain harnesses the energy from these electrons to pump protons across the inner membrane, creating a proton gradient. The potential energy stored in this gradient is then used by ATP synthase to generate ATP via oxidative phosphorylation.

Pyruvate catabolism is a crucial pathway for energy production in all living organisms. It is essential for cellular respiration, the process that allows cells to convert nutrients into energy. Disruptions in pyruvate catabolism can lead to various metabolic disorders and diseases. For example, deficiencies in pyruvate dehydrogenase complex can result in lactic acidosis, a condition characterized by an accumulation of lactic acid in the blood.'
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Proteins (2)

Compounds (20)