Definition:

The glyoxylate cycle is a metabolic pathway. Instead of the two decarboxylation steps of the TCA cycle the key enzymes of the glyoxylate cycle, namely isocitrate lyase and malate synthase, convert isocitrate and acetyl-CoA into succinate and malate. Isocitrate lyase splits the C6-unit into succinate and glyoxylate, which in turn is condensed by malate synthase with acetyl-CoA generating free CoA-SH and malate. The latter is used by malate dehydrogenase to continue the cycle and succinate is released as net product. The intermediate glyoxylate provides the name for this metabolic pathway. The glyoxylate cycle allows cells to convert two acetylCoA units generated by various catabolic processes into C4-units (succinate) which can be used to replenish the TCA cycle or to function as precursors for amino acid biosynthesis or carbohydrate biosynthesis.