BIOL150 Chapter Notes -Antiporter, Passive Transport, Facilitated Diffusion
Document Summary
Diffusion: from a high region of concentration to a region of low concentration. Passive transport: requires no energy to transport, large molecules travel through this transport. Small molecules just move through the layers easily. Dynamic equilibrium is reached when individual molecules or ions continue to move randomly across the membrane in both directions, no net movement. Osmosis: high conc. to low conc, through a selectively permeable membrane. Hypertonic : a greater solute concentration outside than inside; Hypotonic : a lesser solute concentration outside than inside; or. Isotonic : equal solute concentrations outside and inside. Uniport:single type of substance is transported in a single direction along the conc. gradient. Symport: 2 or more different substances are moved in the same direction. Antiport:2 different substances are moved in opposite directions. Facilitated diffusion , polar molecules and ions unable to cross the membrane on their own can diffuse with the help of transport proteins.