1. Active Transport: ATP powers the movement of molecules across cell membranes against their concentration gradient. This means moving substances from an area of low concentration to an area of high concentration, which requires energy. Examples include:

* Sodium-Potassium Pump: Essential for nerve impulse transmission and maintaining cell volume.

* Glucose uptake: Moving glucose into cells for energy production.

2. Muscle Contraction: The sliding filament theory of muscle contraction relies on ATP. ATP provides the energy for the myosin heads to bind to actin filaments and pull them, causing muscle shortening and movement. This is crucial for locomotion, movement of internal organs, and other bodily functions.