CP Bio Diffusion

Brownian motion

random motion of particles

Diffusion

net movement of molecules from high to low concentration

kinetic energy

energy of movement

Concentration

how many solutes are in a solution

Equilibrium

concentration is equal in all areas

Phospholipid

lipid (fat); contains a polar head (hydrophilic) and nonpolar tail (hydrophobic); major component of the cell membrane

Fluid mosaic model

description of cell membrane containing many components

Channel protein

hydrophilic pathway for water and small molecules

Carrier protein

carry specific substances from one side of the membrane to the other

Aquaporin

specific water channel proteins

Polar molecules

molecules containing relative charges (+/-)

Nonpolar molecules

molecules containing no relative charges

Selectively permeable

allows some particles through but not all; based on size and chemical properties (polarity)

Solute

substance being dissolved

Solvent

substance doing the dissolving (water)

Solution

dissolved mixture

Facilitated diffusion

diffusion requiring a protein to cross the membrane

Concentration gradient

difference in concentration on either side of a membrane; the greater the difference, the faster the rate of diffusion

Osmosis

the diffusion of water through an aquaporin

Hypertonic solution

Having a higher concentration of solute in the solution outside of the cell

Hypotonic solution

Having a lower concentration of solute in the solution outside of the cell

Isotonic solution

Having an equal concentration of solute in the solutions both outside and inside the cell