S2) Energy Production II — TCA Cycle & ETC Flashcards
Describe the structure of the mitochondrion
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/500/092/a_image_thumb.png?1513102909)
Pyruvate from Stage 1 (glycolysis) does not enter directly into Stage 3 (TCA cycle).
What reaction occurs?
The link reaction
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/494/428/a_image_thumb.png?1513101093)
Where does the link reaction occur?
Mitochondrial matrix – pyruvate transported from cytoplasm across mitochondrial membrane
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/496/052/a_image_thumb.png?1513101267)
Which enzyme catalyses the link reaction?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/496/355/q_image_thumb.png?1513101293)
Pyruvate dehydrogenase (large multi-enzyme complex)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/496/355/a_image_thumb.jpg?1513101335)
Describe three features of the link reaction
- Reaction is sensitive to Vitamin B1 deficiency (PDH requires factors from B1)
- Reaction is irreversible (key regulatory step)
- Irreversible loss of CO2
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/496/113/a_image_thumb.png?1513101175)
PDH is subject to multiple regulation.
Describe its activation and inhibition in terms of phosphorylation and dephosphorylation
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/496/421/a_image_thumb.png?1513101749)
What is the consequence of PDH deficiency?
Lactic acidosis
Describe three features of the Tricarboxylic Acid Cycle
- Acetyl CoA converted to 2CO2
- Oxidative
- Produces some energy & precursors for biosynthesis
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/497/152/a_image_thumb.png?1513101964)
Where does the TCA cycle occur?
Mitochondria
How many rounds of TCA cycle occur per glucose molecule entering from glycolysis?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/497/406/a_image_thumb.png?1513102087)
What is produced after the two rounds of the TCA cycle occurring per glucose molecule?
- 6 NADH
- 2 FADH2
- 2 GTP
How is the TCA cycle regulated?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/497/854/a_image_thumb.png?1513102313)
Appreciate the biological precusors molecules synthesised from the TCA cycle
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/500/890/q_image_thumb.jpeg?1513103228)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/500/890/a_image_thumb.jpeg?1513103225)
Which three events occur in oxidative phosphorylation?
- Electron transport and ATP synthesis
- NADH & FADH2 re-oxidised
- Large amounts of energy (ATP) produced
![](https://s3.amazonaws.com/brainscape-prod/system/cm/227/499/721/a_image_thumb.png?1513102689)
Where does the ETC occur?
Inner mitochondrial membrane