Diffusion Flashcards
what is diffusion
the movement of particles from high concentration to low concentration until equilibrium is reached
what is simple diffusion
small molecules like O2 and CO2 can diffuse across plasma membrane through bilayer. (small uncharged molecules)
what is facilitated diffusion
substances are helped across membrane by carrier molecules from high concentration to low concentration. Passive transport
what are examples of molecules that use facilitated diffusion
simple sugars, amino acids, nucleotides, charged ions and other nutrients. (large/ charged molecules)
what are examples of molecules that use simple diffusion
O2 and CO2 (small, uncharged molecules)
What is osmosis
diffusion of water passing through a semi permeable membrane from a low solute concentration to a high solute concentration.
what is a solute
a substance dissolved in another substance (solvent) to create the solution.
what is a solvent
a substance that solutes can be dissolved in
what is an example of a solute
salt or glucose
what is an example of a solvent
water
what happens in a hypotonic solution
high H2O outside so water flows inside. pressure builds, cell bursts
what happens in a hypertonic solution
low H2O outside so water flows out. pressure drops. cell becomes dehydrated and shrivels up
what happens in a isotonic solution
concentrations inside and outside are equal so no change occurs.
What are the layers of the plasma membrane
1- phospholipid molecules
2- proteins
3- glycoproteins
4- cholesterol
