Three key ways organisms use ATP are:
- Energy for active transport and movement: ATP provides energy to power active transport mechanisms in cells, such as the sodium-potassium pump, and muscle contraction by enabling myosin heads to detach and reattach to actin filaments for movement.
- Synthesis of molecules: ATP supplies energy for the synthesis of new cells, amino acids, proteins, and other molecules necessary for growth and repair.
- Intracellular signaling and metabolic regulation: ATP serves as a substrate for kinases in phosphorylation reactions during signal transduction pathways and activates secondary messengers like cyclic AMP, which regulate various cellular activities.
These uses reflect ATP's role as a universal and immediate energy currency essential for maintaining life processes in all organisms.