II. Membrane Transport Two types: Passive & Active A. Passive Transport - does not require energy 1. Diffusion - process where molecules move from an area where they are more concentrated to an area where they are less concentrated

II. Membrane Transport

II. Membrane Transport 2. Osmosis - the diffusion (high to low concentration) of water through a selectively permeable membrane

II. Membrane Transport Type of Solution Plant Cell Animal Cell __________________ - net flow of water is into a cell __________________ – water moves in and out of the cell at equal rates __________________ - net flow of water is out of the cell

II. Membrane Transport 3. Facilitated Diffusion – When a carrier molecule transports solute molecules across the membrane Speed up diffusion Carry large molecules that can’t diffuse quickly across cell membrane

II. Membrane Transport

Review of types of Passive Transport

II. Membrane Transport B. Active Transport – the movement of any substance across a cell membrane with the use of chemical energy Requires energy & a carrier protein Against the concentration gradient – moving low to high (paddling up a river)

II. Membrane Transport Transport proteins – Special transport molecules in the cell membrane move molecules across the cell membrane Moves particles from low concentration to high concentration – pumps

II. Membrane Transport Endocytosis – bringing large particles into the cell Pinocytosis – Movement of solutes or fluids into the cell. “Cell drinking” Phagocytosis – Movement of large food particle or whole microorganisms into the cell. “Cell eating”

II. Membrane Transport

II. Membrane Transport Exocytosis – removal or large particles from a cell