Final answer:
The creatine phosphate system transfers high energy phosphate to ADP to dephosphorylate ATP through a reaction catalyzed by creatine kinase, providing energy for short bursts of muscle activity.
Step-by-step explanation:
The system that transfers high energy phosphate from CP (creatine phosphate) to rephosphorylate ATP from ADP is a fast reaction that occurs in muscles. Creatine phosphate stores energy in its phosphate bonds and, upon muscle contraction, it transfers this phosphate to ADP to form ATP and creatine, a reaction catalyzed by the enzyme creatine kinase. This efficient process provides the quick burst of energy required for the initial seconds of muscle activity, often utilized in activities that demand short, high-intensity efforts like weightlifting or sprinting.