Tori asked in Science & MathematicsBiology · 10 years ago

HELP with the KREBS CYCLE??!!!!!?

ok.. all i need is some basic info on the krebs cycle process. please help because so many people have told me different answers and have just completely confused me so could you guys please help and try to make it less complicated. ty so very much :)))

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  • 10 years ago
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    Krebs cycle -

    - Condensation - Two carbon acetyl CoA combines with 4 carbon oxaloacetic acid in presence of enzyme citrate synthetase to form 6-carbon citric acid. Water molecule is used, CoA is released.

    - Dehydration -Citric acid undergoes dehydration to form a 6-carbon compound cis-aconitic acid in presence of enzyme aconitase and Fe++ ions.

    - Hydration - Cis-aconitic acid is converted to iso-citric acid by water molecule. Enzyme aconitase and Fe++ ions are used.

    - Dehydrogenation -Isocitric acid undergoes oxidation in presence of iso-citric dehydrogenase to form oxalo-succinic acid. This releases hydrogen atoms that are used for reduction of NAD and NADH2.

    - Decarboxylation - Oxalosuccinic acid, which is 6-carbon compound undergoes decarboxylation to form 5-carbon acid like alpha-ketoglutaric acid and carbondioxide. Enzyme used is decarboxylase with Mn++.

    - Dehyrogenation and Decarboxylation - 4-carbon succinyl CoA is formed by oxidation decarboxylation alpha-ketoglutaric acid. In this step one molecule of NAD is reduced to NADH2 and Carbondioxide is released. One molecule of CoA is used and alpha-ketoglutaric dehydrogenase catalyses the reaction.

    - Formation of GTP -Succinyl CoA is hydrolysed to succinic acid in presence of enzyme succinnc thiokinase. GDP is converted to GTP. water molecule is used up and CoA is given out.

    - Dehydrogenation -Succinic acid undergoes dehydrogenation in presence of enzyme succinic acid dehydrogenase to form fumaric acid. Hydrogen atom released are accepted by FAD and gets reduced to FADH2.

    - Hydration - With addition of a molecule of water in presence of enzyme fumarase, fumaric acid is converted into malic acid.

    - Dehydrogenation -Malic acid undergoes dehydrogenation to produce oxaloacetic acid which combines with acetyl CoA to produce citric acid. Hydrogen released is used to reduce NAD.

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