Final answer:
Glycolysis is primarily regulated by three key enzymatic steps: hexokinase, phosphofructokinase, and pyruvate kinase. These enzymes control the rate of glycolysis and are influenced by factors such as ATP levels, citrate, pH, and fructose-1,6-bisphosphate levels. option e is correct
Step-by-step explanation:
option e is correct Glycolysis, the catabolic process in which glucose is converted into pyruvate, is primarily regulated by three key enzymatic steps: hexokinase (step 1), phosphofructokinase (step 3), and pyruvate kinase (step 10). These steps are highly regulated and play a crucial role in controlling the rate of glycolysis. For example, hexokinase catalyzes the phosphorylation of glucose, which helps prepare the compound for further reactions. Inhibition of hexokinase leads to glucose diffusing out of the cell, preventing it from entering the respiration pathways.
Phosphofructokinase is another important regulatory enzyme in glycolysis. Its activity is influenced by factors such as ATP levels, citrate, and pH. High levels of ATP, citrate, or a lower pH decrease phosphofructokinase's activity, regulating the flow of glucose through glycolysis.
Pyruvate kinase, the enzyme that catalyzes the final step of glycolysis, is also regulated. Pyruvate kinase's activity is increased by an increase in fructose-1,6-bisphosphate levels. Conversely, it is inhibited when no more energy is needed and alanine is in adequate supply. Phosphorylation by a kinase reduces pyruvate kinase's activity, while dephosphorylation by a phosphatase reactivates it.
Glycolysis is regulated primarily by three strongly exergonic, nonequilibrium reactions. The key regulatory steps in glycolysis are catalyzed by the enzymes hexokinase, phosphofructokinase, and pyruvate kinase. These steps are early in the pathway, involve ATP hydrolysis, and are strongly exergonic, making them points of regulation. Phosphofructokinase is the main enzyme controlled in glycolysis, and is allosterically inhibited by high levels of ATP, citrate, and a lower pH, while the activity of pyruvate kinase is increased in the presence of fructose-1,6-bisphosphate, showing it is allosterically regulated and also influenced by phosphorylation state.