AP BIOLOGY

Detailed explanation-1: -Simple diffusion and osmosis are both forms of passive transport and require none of the cell’s ATP energy.

Detailed explanation-2: -There are three main types of passive transport: Simple diffusion – movement of small or lipophilic molecules (e.g. O2, CO2, etc.) Osmosis – movement of water molecules (dependent on solute concentrations) Facilitated diffusion – movement of large or charged molecules via membrane proteins (e.g. ions, sucrose, etc.)

Detailed explanation-3: -The simplest forms of transport across a membrane are passive. Passive transport does not require the cell to expend any energy and involves a substance diffusing down its concentration gradient across a membrane.

Detailed explanation-4: -5. Is diffusion active or passive? Diffusion is a type of passive transport that does not require energy. Diffusion helps the molecules to move from a region of high concentration to a region of low concentration.

Detailed explanation-5: -In simple diffusion, small noncharged molecules or lipid soluble molecules pass between the phospholipids to enter or leave the cell, moving from areas of high concentration to areas of low concentration (they move down their concentration gradient).