Diffusion & Osmosis Ch 8

Diffusion Definition: Net movement of particles from an area of _______ concentration to an area of ______ concentration Example: _____________________________ high low The smell of popcorn traveling across the room

Diffusion results from the _________ movements of particles (Brownian motion) Diffusion is a ________ process random SLOW

3 factors affect the ________ (how quickly or slowly) of diffusion ________________ If you increase ________ then ______________________ ________________ If you increase ________ then __________________________ ________________ If you increase ________ then _______________________rate Temperature Concentration Pressure Temp. it will move more Conc. it will diffuse more rapidly Pressure it will increase diffusion

Eventually… the particles will become _______ distributed The condition in which there is continuous movement, but no overall concentration change is called __________________ evenly dynamic equilibrium

The difference in concentration of a substance across a space is called _______________________ concentration gradient High concentration Low concentration concentration gradient

In the case with diffusion, particles are moving from an area of _____ concentration to an area of _____ concentration; therefore, the substance is said to move ______ the concentration gradient. high low with

Another example of diffusion: Oxygen in the air sacs of lungs  diffuses into capillaries Particles constantly move & bounce off each other and other surfaces

Osmosis Definition: Diffusion of water across a _________________ membrane Osmosis is a special example of __________ Semi-permeable diffusion

Osmosis Example: Absorption of water by plant roots

Osmosis It is important to notice that __________________ molecules do not cross the membrane, but _______ molecules do cross during osmosis Osmosis occurs in both plant and animal cells and there are three conditions that typically appear. large impermeable H20H20H20H20

Isotonic Solution Concentration of dissolved substances in the solution is the _______ as the concentration of dissolved substances inside the cell. Hypotonic solution Concentration of dissolved substances is _______ in the solution outside the cell than the concentration inside the cell Hypertonic solution Concentration of dissolved substances is ________ outside than the concentration inside the cell same less greater

ISOTONIC SOLUTION 10% salt cell HYPOTONIC SOLUTION 2% salt 10% salt cell HYPERTONIC SOLUTION 25% salt 10% salt cell

Normal Cells in Isotonic Solution Cells in Hypertonic Solution Cells in Hypotonic Solution

ISOTONIC SOLUTION 10% salt cell HYPOTONIC SOLUTION 2% salt 10% salt cell HYPERTONIC SOLUTION 25% salt 10% salt cell Equal movement in and out More H 2 O in than out More H 2 O out than in

Here is what happens when more water exits or more water enters