Creatine kinase is an enzyme found in various tissues, including muscles, the brain, and the heart. It plays a crucial role in energy production by converting creatine and adenosine triphosphate (ATP) into phosphocreatine and adenosine diphosphate (ADP). This process helps supply energy during high-intensity activities, such as exercise. Elevated levels of creatine kinase in the blood can indicate muscle damage or stress, making it a useful biomarker for diagnosing conditions like heart attacks or muscle disorders. Medical professionals often measure creatine kinase levels to assess the extent of injury or monitor recovery in patients.