Citric Acid Cycle Flashcards
1
Q
How did Szent-Gyögi, Knoop, and Krebs contrubute to the discovery of the citric acid cycle?
A
Szent-Gyögi - found that certain organic acids can stimulate a burst of respiration
Knoop - found that citric acid was oxidized to alpha-ketoglutarate
Krebs - found that that blockage of malonate lead to the accumulation of succinate and discovered the cyclic idea
2
Q
What are the 8 steps of the krebs cycle?
A
- condensation of oxaloacetate with acetyl CoA
- Formation of isocitrate
- Oxidiative decarboxylation of isocitrate
- oxidation of alpha-ketoglutarate
- conversion of succinyl CoA to succinate
- oxidation of succinate to fumarate
- Hydration of fumerate to malate
- Oxidation of malate to oxaloacetate
3
Q
What mechanism does the oxidation of alpha-ketoglutarate to succinyl CoA use?
A
the same mechanism as the PDH complex
4
Q
Describe the reaction mechanism of the conversion of succinyl CoA to succinate.
A
- Inorganic phosphate displaces coenzyme A of succinyl CoA to form a high-energy acyl phosphate
- A reactive histidine accepts phosphate releasing succinate
- The transfer of the phosphate contributes to releasing ATP
5
Q
How much NADH and FADH2 is produced from one turn of the cycle?
A
3 NADH and 1 FADH2
