Define active transport? Discuss with suitable examples

Cells continuously exchange materials with their environment to maintain homeostasis and perform essential functions. This movement of substances across the cell membrane occurs through: Passive transport (which does not require energy) Active transport (which requires energy) Active Transport Active transport is a biological process in which molecules or ions move across the cell membrane against their concentration gradient (from a lower concentration to a higher concentration). Unlike passive transport, which relies on natural diffusion, active transport requires energy in the form of ATP (adenosine triphosphate) to drive molecules across the membrane. This energy-driven transport is essential for maintaining cellular functions, such as nutrient uptake, waste removal, nerve impulse transmission and maintaining ion balance. Active transport is crucial for cells because it allows them to maintain an internal environment that d...