1.3 Osmosis and Diffusion

Diffusion, Osmosis, and the Cell Membrane Diffusion – is the movement of particles from an area of higher concentration to an area of lower concentration (Ex. Perfume)   Concentration – the amount of a substance in a given space Osmosis – is the movement of water from an area of higher concentration to an area of lower concentration (Ex. Limp carrot in water) through a selectively permeable membrane

Movement across a Membrane Cell membrane is selectively permeable = only some things in Cell membrane can be compared to a coffee filter Diffusion is one way that particles move across the cell membrane If one side of the membrane has a higher concentration of particles they will move across the membrane until both sides have the same amount = this means an equilibrium is reached Particles will continue to move back and forth but there will be the same number on either side Example: oxygen in our cells lungs to the blood cells

Reverse Osmosis Reverse Osmosis – movement of water from a high to a low concentration – backwards – this requires pressure to push the molecules Used for filtering water, purifying maple syrup and juice, and treating sewage

Your Turn Questions P. 49 #1-12 Make sure your lab write up is handed in