HLSC 1200U Lecture Notes - Lecture 2: Osmotic Pressure, Facilitated Diffusion, Passive Transport
Document Summary
Topics: transport into and out of the cell, metabolism of the cell, generation of energy by the cell. Substances or water is moved down a concentration gradient. (region of high concentration to a region of low concentration). Substances are moved against a concentration gradient. (low to high concentration) Substances enter or leave the cell in a package. (vesicle) Does not require any special channels or carriers. Very specific: one solute can pass through any channel. Gated channels: allow substances to come in or out. (open=active) (closed=inactive) Aquaporins: specific type of pores that allow water to through cell membrane. Very specific: one solute can use each type of carrier. Usually reversible: depending on concentration inside and outside of cell. Channel mediated more substances outside of the cell tan the inside, molecule is charged, pores allow the molecule to go through. Either open in which case it works or closed where nothing can go through.