Question

Which of the following statements about phosphocreatine (PCr) and exercise is true?

1) PCr is activated instantly during endurance activity.
2) PCr can replenish ATP rates fast enough to meet energy demands of quick, powerful actions (e.g., shot put or bench press).
3) PCr can be stored in large quantities in the muscles.
4) Taking creatine supplements will improve performance in athletes who undertake multiple bursts of sustained activity.

Answer 1

Phosphocreatine (PCr) is a molecule that can store energy in muscles and is quickly converted to ATP during muscle contraction. Creatine supplements may increase ATP production and power output, but their effectiveness in improving performance in athletes is debated.

Step-by-step explanation:

Phosphocreatine (PCr) is a molecule that can store energy in its phosphate bonds. It acts as an energy reserve in muscles and can be quickly converted to ATP during the initial stages of muscle contraction. However, PCr can only provide energy for about 15 seconds, at which point another energy source is needed.

Taking creatine supplements can increase the amount of creatine available in cells, potentially resulting in more ATP production and increased power output. However, the effectiveness of creatine supplements in improving performance in athletes who undertake multiple bursts of sustained activity is still a topic of debate.