citrateisomerisaatio

Citrate isomerisation is a crucial step in the citric acid cycle, also known as the Krebs cycle or TCA cycle. This biochemical process involves the conversion of citrate into its isomer, isocitrate. The reaction is catalyzed by the enzyme aconitase, which facilitates the reversible rearrangement of the citrate molecule. Specifically, aconitase removes a water molecule from citrate and then adds it back in a different position, effectively moving a hydroxyl group. This seemingly minor structural change is essential for the subsequent oxidation steps of the citric acid cycle. Citrate isomerisation occurs in the mitochondrial matrix of eukaryotic cells and the cytoplasm of prokaryotic cells. The enzyme aconitase is a metalloprotein containing an iron-sulfur cluster, which is vital for its catalytic activity. The overall purpose of this isomerization is to prepare the molecule for decarboxylation, the removal of a carbon dioxide molecule, which releases energy that is then captured in the form of reduced electron carriers like NADH and FADH2. These reduced carriers then proceed to the electron transport chain to generate ATP, the primary energy currency of the cell. The citrate isomerisation step ensures that the molecule is in the correct configuration for efficient energy extraction.