Target type: biologicalprocess
The chemical reactions and pathways resulting in the breakdown of glyoxylate, the anion of glyoxylic acid, HOC-COOH. [ISBN:0198506732]
The glyoxylate cycle, also known as the glyoxylate shunt, is a metabolic pathway that occurs in plants, bacteria, fungi, and some protists. It is a modification of the citric acid cycle (TCA cycle) that allows these organisms to grow on two-carbon compounds like acetate.
The glyoxylate cycle bypasses the decarboxylation steps of the TCA cycle, allowing for the net synthesis of four-carbon compounds from two-carbon compounds. This is crucial for organisms that cannot synthesize carbohydrates from carbon dioxide (e.g., plants in the dark or some bacteria), as it enables them to use acetate as a carbon source for growth.
The glyoxylate cycle consists of four key reactions:
1. **Isocitrate lyase**: This enzyme cleaves isocitrate into glyoxylate and succinate.
2. **Malate synthase**: This enzyme combines glyoxylate with acetyl-CoA to form malate.
3. **Malate dehydrogenase**: This enzyme oxidizes malate to oxaloacetate.
4. **Phosphoenolpyruvate carboxykinase (PEPCK)**: This enzyme decarboxylates oxaloacetate to phosphoenolpyruvate.
The glyoxylate cycle is tightly regulated by a variety of factors, including the availability of substrates, the energy status of the cell, and the growth conditions.
**Overall, the glyoxylate cycle plays a vital role in the metabolism of organisms by enabling them to utilize acetate as a carbon source for growth and biosynthesis.**'
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Protein | Definition | Taxonomy |
---|---|---|
4-hydroxy-2-oxoglutarate aldolase, mitochondrial | A 4-hydroxy-2-oxoglutarate aldolase, mitochondrial that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q86XE5] | Homo sapiens (human) |
Compound | Definition | Classes | Roles |
---|---|---|---|
chelidamic acid | |||
dipicolinic acid | dipicolinic acid : A pyridinedicarboxylic acid carrying two carboxy groups at positions 2 and 6. | pyridinedicarboxylic acid | bacterial metabolite |