fosfókreatín

Fosfokreatín, also known as creatine phosphate or phosphocreatine, is a high-energy organic molecule that plays a crucial role in cellular energy metabolism, particularly in tissues with high and fluctuating energy demands such as skeletal muscle and the brain. It is formed by the transfer of a phosphate group from adenosine triphosphate (ATP) to creatine, catalyzed by the enzyme creatine kinase. This reaction effectively stores energy in a readily accessible form.

During periods of intense muscular activity, when ATP is rapidly consumed, the stored phosphate group from fosfokreatín can be quickly transferred back to adenosine diphosphate (ADP) to regenerate ATP. This process, also catalyzed by creatine kinase, provides a rapid burst of energy that is essential for short-duration, high-intensity activities like sprinting or weightlifting. Fosfokreatín serves as a buffer for cellular ATP levels, ensuring that sufficient energy is available to maintain cellular function during demanding tasks.

The concentration of fosfokreatín in muscle tissue is significantly higher than that of ATP, allowing it to sustain ATP levels for several seconds of maximal exertion. Once the fosfokreatín stores are depleted, the body must rely on other energy systems, such as glycolysis and oxidative phosphorylation, to produce ATP, which are slower but can provide energy for longer durations. The body can replenish fosfokreatín stores during rest periods by reversing the creatine kinase reaction.