“Kerbs Cycle”

                                             “Kerbs Cycle”

1) Pyruvate in cytosol will go through reactions and will convert to 2 carbon molecules. One of the 3 carbons in pyruvate will be released as carbon dioxide. The remainder is called Acetyl group that will combine to coenzyme A (co-A) and will provide Acetyl-CoA

2) It is a cyclical metabolic pathway occurs in mitochondria matrix

3)  During this cycle the carbon atom from glucose that entered to the glycolysis will be oxidized.

4) This cycle has made of 9 step reactions with following names   :         

Reaction 1: condensation

Reaction 2 and 3: Isomerization

Reaction 4:  The first Oxidation

Reaction 5: The second Oxidation

Reaction 6: Substrate- level phosphorylation

Reaction 7: The third Oxidation

Reaction 8 and 9:  Regeneration of oxaloacetate and the fourth Oxidation

5) For each glucose, 2 acetyl-CoA will enter the kerbs cycle that carries 2 carbons

6) Acetyl will react to oxaloacetate to produce citrate (6 carbon molecule)  

7) This molecule (citrate) will go through 5 series of reactions and 4 carbon molecules called succinate will be forms. 2 of the reactions are oxidation reaction and will release 2 carbon dioxides. 2 of the reactions are reduction reactions which produce NADH from reduction of NAD.

8) In the 6^th stage, ATP will be produced by (substrate-level phosphorylation). In this process phosphate group replace CoA and substrate succinct will bound to the enzyme. Phosphate will be added to (GTP) and terminal of (GTP) will be transferred to ADP to produce ATP. In somce cells, cell will use GTP to make their own energy.

9) 2 of the actions that will take place from stage 7-9 are oxidation. These electrons will be used to produce ATP in the oxidative phosphorylation pathway. This reaction is coupled to reduction of NAD to form NADH and FAD to form FADH₂.

10) The last product of all of the reactions is oxaloacetate. It will be ready to react to more Acetyl-CoA that will be entered the kerbs cycle.