ACTIVE AND PASSIVE TRANSPORT OF SUBSTANCES THROUGH BIOMEMBRANES

Abstract

This thesis discusses the mechanisms of active and passive transport across biomembranes, their molecular basis, and their functional significance in cellular metabolism. Passive transport enables the movement of substances down their concentration gradient without energy expenditure, including diffusion and osmosis. Active transport requires ATP energy to move ions and molecules against their gradients. The main forms of active transport—such as symport, antiport, and membrane pumps (e.g., Na⁺/K⁺-ATPase)—are described in detail. This work aims to explain the essential role of membrane transport in cell physiology.