Final answer:
The regulation of the glycolysis and citric acid cycle pathways is determined by factors such as enzyme activity, substrate availability, and product inhibition.
Step-by-step explanation:
The regulation of the glycolysis and citric acid cycle pathways is determined by several factors.
- Phosphofructokinase: This enzyme is a key regulatory site in glycolysis. High levels of ATP, citrate, or a lower pH decrease the enzyme's activity.
- Pyruvate kinase: This enzyme is involved in the last step of glycolysis. Its activity is increased when fructose-1,6-bisphosphate levels increase and inhibited when there is no need for more energy.
- Substrate availability and product inhibition: The regulation of the citric acid cycle is largely determined by the availability of substrates and the inhibition of certain enzymes by its products.
Other factors that affect the efficiency of the citric acid cycle include the levels of acetyl groups, NADH, and the regulation of enzymes through phosphorylation and dephosphorylation.