Understanding Passive Transport
Passive transport is the movement of substances across cell membranes without using energy. It all starts with solutions - a mixture of a solute (the dissolved substance like sugar or salt) and a solvent (the substance doing the dissolving, often water).
Diffusion happens when molecules naturally move from areas of high concentration to areas of low concentration. A special type of diffusion called osmosis focuses specifically on water molecules moving across cell membranes. These movements follow the concentration gradient - basically the difference in solute concentration from one area to another.
When molecules are evenly distributed throughout a space, we call this equilibrium. Though molecules are still moving, there's no net change in their distribution. In a hypotonic solution, there's a higher concentration of solute inside the cell than outside, causing water to flow into the cell until balance is reached.
💡 Think of concentration like a crowd at a concert. Diffusion is like people naturally spreading out from a packed area to less crowded spaces without being told to move.
