Kreb Cycle and steps involved in kreb cycle
- 2. KREBS CYCLE ASAMIYA SUHAIL KHAN PROGRAM LEADER EMERGENCY & INTENSIVE CARE TECHNOLOGY
- 4. Hans AdolfKrebs Biochemist; born in Germany, worked in Britain. His discovery in 1937 of the KREBS CYCLE of cycle reactions was critical to the understanding of cell metabolism and earned him the 1953 Nobel Prize for Physiology or Medicine.
- 5. KrebsCycle •TheKrebscycle refers to acomplex seriesof chemical reactions that produce carbon dioxide andAdenosine triphosphate (ATP), acompound rich in energy. the created compound then goes through aseriesof changesthat produce energy.
- 6. Function of KrebCycle •Makes 3NADH •Makes 1FADH2 •Makes 1ATP
- 9. StepOne •The acetic acid subunit of acetyl CoA is combined with oxaloacetate to form a molecule of citrate . The acetyl coenzyme A acts only as a transporter of acetic acid from one enzyme to another.
- 10. Step2 •The cit ric acid molecule isomerizat ion. A hydroxyl group and undergoes an a hydrogen molecule are removed from t he citrate structure in the form of water. The two carbons form a double bond unt il t he wat er Thus, isocitrate is molecule is added back. formed.
- 11. Step3 •In this step, the isocitrate molecule is oxidized by a NAD molecule. The NAD molecule is reduced by the hydrogen atom and the hydroxyl group. This structure is very unstable, so a molecule of CO2 is released creating alpha- ketoglutarate.
- 12. Step4 •In this step, our friend, coenzymeA, returns to oxidize the alpha-ketoglutarate molecule. Amolecule of NAD is reduced again to form NADH and leaves with another hydrogen. This instability causesacarbonyl group to be released ascarbon dioxide and athioester bond is formed in its place between the former alpha- ketoglutarate andcoenzymeAto create amolecule of succinyl-coenzymeA complex.
- 13. Step5 •A water molecule sheds its hydrogen atoms to coenzyme A. Then, a free- floating phosphate group displaces coenzyme A and forms a bond with the succinyl complex. The phosphate is then transferred to amolecule of GDP to produce an energy molecule of GTP. I t leaves behind amolecule of succinate .
- 14. Step6 •In this step, succinate is oxidized by a molecule of FAD ( Flavin adenine dinucleotide). The FAD removes two hydrogen atoms from the succinate and forces adouble bond to form between the two carbon atoms, thus creating fumarate .
- 15. Step 7 •An enzyme adds water to the fumarate molecule to form malate. The malate is created by adding one hydrogen atom to acarbon atom and then adding ahydroxyl group to acarbon next to aterminal carbonyl group.
- 16. Step8 •In this final step, the malate molecule is oxidized by aNAD molecule. The end product is oxaloacetate which can then combine with acetyl- coenzyme A and begin the Krebs cycle all over again.