Cell Transport: Moving Materials Across Membranes
Your cells need to move substances in and out constantly, which happens through passive transport and active transport. Passive transport requires no energy and moves substances from high to low concentration areas - like rolling downhill.
Diffusion is when molecules spread out naturally from crowded to less crowded areas until they reach equilibrium. Meanwhile, osmosis is specifically the diffusion of water through a cell membrane. The direction water flows depends on solution types: isotonic (equal concentration, cells maintain shape), hypotonic (cells swell as water flows in), or hypertonic (cells shrink as water flows out).
Some molecules can't pass through the membrane easily on their own. These use facilitated diffusion, where special protein channels change shape to help these molecules cross the membrane without using energy.
💡 Think of passive transport like people naturally spreading out in an empty room (no energy needed), while active transport is like climbing stairs (requires energy)!
