Lecture 3 - Anaplerotic Reactions Flashcards
What are anaplerotic reactions?
Balancing or “filling up” reactions
What are the 4 anaplerotic reactions of TCA cycle?
1) Pyruvate carboxylase
2) Phosphoenolpyruvate carboxykinase
3) Phosphoenolpyruvate carboxylase
4) Malic enzyme
Where does the pyruvate carboxylase reaction take place?
Liver and kidneys
What activates pyruvate carboxylase?
Acetyl-CoA
Which of the 4 anaplerotic reactions of TCA cycle are gluconeogenetic?
- Pyruvate carboxylase
- Phosphoenolpyruvate carboxykinase
Where does the phosphoenolpyruvate carboxykinase reaction take place?
Heart and muscle
Where does the phosphoenolpyruvate carboxylase reaction take place?
Higher plants, yeast, and bacteria
Which of the 4 anaplerotic reactions of TCA cycle are important for fatty acid synthesis?
- Pyruvate carboxylase
- Malic enzyme
What happens in the pyruvate carboxylase reaction?
Pyruvate is converted to oxaloacetate
What are the cofactors in the pyruvate carboxylase reaction?
- CO2 in
- ATP + H2O -> ADP + Pi
- Biotin
What happens in the phosphoenolpyruvate carboxykinase reaction?
Phosphoenolpyruvate is converted to oxaloacetate
What are the cofactors in the phosphoenolpyruvate carboxykinase reaction?
- CO2 in
- GDP -> GTP
What activates phosphoenolpyruvate carboxylase?
Fructose 1,6-bisphosphate
What happens in the phosphoenolpyruvate carboxylase reaction?
Phosphoenolpyruvate is converted to oxaloacetate
What are the cofactors in the phosphoenolpyuvate carboxylase reaction?
- CO2 in
- Pi out
