When is creatine phosphate made?

When is creatine phosphate made?

• A. During heavy activity
• B. When a muscle is at rest
• C. During sleep
• D. During rapid movement

Answer: (B)

Creatine phosphate is formed when energy demand is low and ATP is plentiful, typically during rest. The enzyme creatine kinase transfers a phosphate from ATP to creatine, producing phosphocreatine and ADP. This creates a rapid-energy reserve that can be tapped when a quick burst of activity starts, as phosphocreatine donates its phosphate back to ADP to rapidly regenerate ATP. It isn’t made during intense or rapid movements, when the muscle needs to pull ATP from phosphocreatine to sustain contraction, and while resting states like sleep also involve low energy demand, the general resting state best describes the conditions under which synthesis occurs.

Creatine phosphate is formed when energy demand is low and ATP is plentiful, typically during rest. The enzyme creatine kinase transfers a phosphate from ATP to creatine, producing phosphocreatine and ADP. This creates a rapid-energy reserve that can be tapped when a quick burst of activity starts, as phosphocreatine donates its phosphate back to ADP to rapidly regenerate ATP. It isn’t made during intense or rapid movements, when the muscle needs to pull ATP from phosphocreatine to sustain contraction, and while resting states like sleep also involve low energy demand, the general resting state best describes the conditions under which synthesis occurs.