Final answer:
Glycolytic enzymes in muscle cells are active during glycogenolysis to rapidly provide energy for exercise or 'fight or flight' responses. Hormonal signaling ensures the rapid conversion of glycogen to glucose, fueling the glycolysis pathway. This process is critical for the immediate energy needs of muscles during vigorous activity.
Step-by-step explanation:
During glycogenolysis, glycolytic enzymes are active in muscle cells because these enzymes are part of a crucial metabolic pathway that rapidly provides energy for muscular activity. The breakdown of muscle glycogen to produce glucose, which then undergoes glycolysis, is important particularly during vigorous exercise. There are several reasons why muscle glycolytic enzymes are active:
- The immediate need for ATP during increased exertion makes the quick breakdown of glycogen to glucose and its subsequent metabolism through glycolysis essential.
- Signal transduction pathways involving hormones like adrenaline lead to the activation of glycogen phosphorylase, the enzyme responsible for breaking down glycogen into glucose, via a phosphorylation cascade that involves cAMP and PKA (protein kinase A).
- This process ensures that muscle cells have a readily available supply of glucose for energy, which is vital for the 'fight or flight' response during short-term emergencies.
Ultimately, the enzymatic activities ensure both the supply of glucose for immediate energy needs and the inhibition of opposite processes like glycogen synthesis that would consume energy instead of producing it.