What happens to ADP during the action of creatine kinase?

During the action of creatine kinase, ADP obtains a phosphate group from creatine phosphate. This reaction is crucial for providing an immediate source of energy for muscles during short bursts of intense activity.

Creatine phosphate serves as a reservoir for high-energy phosphate groups that can quickly regenerate ATP from ADP. When ATP levels are low, as is the case during intense muscle contraction, creatine kinase facilitates the transfer of a phosphate group from creatine phosphate to ADP, converting it into ATP. This process allows for a rapid replenishment of ATP, which is essential for continued muscle function.

The other options do not accurately represent the role of creatine kinase or the processes occurring in the muscle tissue during energy production. Glucose metabolism and lactic acid production are part of different energy pathways and not directly involved in the immediate action of creatine kinase.