BIO310H5 Lecture 3: BIO310; Lecture 3
Document Summary
Passage across the membrane can be: semi-permeable or selectively permeable) Permeable: substances can move across the cell membrane (permeable, Impermeable: substances cannot move across the cell membrane. Passive: from areas of high to low concentration (gradient) Active: molecules move against the concentration gradient (fueled by energy. Cell spends energy=active transport and if it doesn"t = passive transport from the hydrolysis of atp) Materials can cross the cell membrane by: Movement of molecules from one location to another solely as a result of their random thermal motion. Net fluxes always proceed from regions of higher concentration to lower concentration. Net fluxes depend on several factors: temperature, mass of the molecule, surface area, and medium through which the molecules move. Due to hydrophobic core of lipid bilayer. Gases (i. e. co2 , o2 , no, and co) Molecule should break all of its hydrogen bonds with water. Channels, carriers and pumps allow transport across biological membranes.