1. Active Transport: ATP powers the movement of molecules across cell membranes against their concentration gradient. This means moving molecules from an area of low concentration to an area of high concentration, which requires energy. Examples include:
* Sodium-potassium pump: Essential for maintaining the electrochemical gradient across nerve cell membranes, crucial for nerve impulses.
* Glucose uptake: Moving glucose into cells against its concentration gradient for cellular respiration.
2. Muscle Contraction: The breakdown of ATP provides the energy for muscle fibers to shorten and contract. This allows for movement, locomotion, and maintaining posture.
* Myosin heads: Proteins in muscle fibers that bind to actin filaments and use ATP energy to pull them closer, causing muscle contraction.
Key takeaway: ATP is like a rechargeable battery within the cell. It readily releases energy when needed, allowing cells to perform vital processes like transporting molecules and powering movement.
