The main source of energy for cellular processes is adenosine triphosphate (ATP). ATP is a high-energy molecule that serves as a universal energy currency within cells. It is produced through cellular respiration and photosynthesis, storing energy in its phosphate bonds. When energy is required for cellular activities, such as muscle contraction, active transport, or biosynthesis, ATP can be hydrolyzed to release energy. This process is vital for maintaining cellular functions and facilitating various biochemical reactions necessary for life. ATP’s role makes it essential for sustaining biological activities.