Kreb Cycle. Describe steps occurred in the cycle.

3. Step 1
● Acetyl CoA combines with a four-carbon acceptor molecules, oxaloacetate
● Oxaloacetate to form a six-carbon molecules called citrate.

4. Step 2
● Citrate is rearranged to form isocitrate by enzyme acontinase
● Accomplished by removal and addition of water

5. Step 3
● Isocitrate is oxidised, forming α-ketoglutarate (5-carbon molecules) and one
molecules of CO2
● NAD+ is reduced to NADH
● Perform by enzyme isocitrate dehydrogenase

6. Step 4
● Α-ketoglutarate (5-carbon) is oxidised to form a 4-carbon molecule which
pick up coenzyme A, forming succinyl-CoA (4-carbon)
● One molecule of reduced NAD is formed and carbon dioxide is released
● Enzyme, α-ketoglutarate dehydrogenase, is involved

7. Step 5
● Succinyl-CoA (4-carbon) is converted to succinate (4-carbon)
● One molecule of GTP is formed
● Enzyme, succinyl-CoA synthetase, is involved

8. Step 6
● Succinate is oxidized, forming Fumarate
● Two hydrogen atoms are transferred to FAD+
○ FADH2
● FADH2 transfers its electrons directly to the ETC
○ Localization of the enzyme (succinate
dehydrogenase)

9. Step 7
● Water is added to fumarate to convert it to maltate.

10. Step 8
● Oxaloacetate is regenerated by oxidation of malate
● NAD+ is reduced into NADH

11. THANKYOU

12. Step 1
● Acetyl CoA combines with a four-carbon acceptor molecules, oxaloacetate
● Oxaloacetate to form a six-carbon molecules called citrate.

13. Step 2
● Citrate is rearranged to form isocitrate by enzyme acontinase
● Accomplished by removal and addition of water

14. Step 3
● Isocitrate is oxidised, forming α-ketoglutarate (5-carbon molecules) and one
molecules of CO2
● NAD+ is reduced to NADH
● Perform by enzyme isocitrate dehydrogenase

15. Step 4
● Α-ketoglutarate (5-carbon) is oxidised to form a 4-carbon molecule which
pick up coenzyme A, forming succinyl-CoA (4-carbon)
● One molecule of reduced NAD is formed and carbon dioxide is released
● Enzyme, α-ketoglutarate dehydrogenase, is involved

16. Step 5
● Succinyl-CoA (4-carbon) is converted to succinate (4-carbon)
● One molecule of GTP is formed
● Enzyme, succinyl-CoA synthetase, is involved

17. Step 6
● Succinate is oxidized, forming Fumarate
● Two hydrogen atoms are transferred to FAD+
○ FADH2
● FADH2 transfers its electrons directly to the ETC
○ Localization of the enzyme (succinate
dehydrogenase)

18. Step 7
● Water is added to fumarate to convert it to maltate.

19. Step 8
● Oxaloacetate is regenerated by oxidation of malate
● NAD+ is reduced into NADH

20. THANKYOU