Movement of materials *Diffusion *Osmosis *Passive/Active transport

24/ ! Materials are ALWAYS on the move!  Cells are constantly trying to maintain HOMEOSTASIS!  When the amount of material INSIDE the cell is different than the amount of material OUTSIDE, a concentration gradient exists.  When the molecules are even throughout a space - it is called EQUILIBRIUM

Diffusion  process by which molecules move from areas of high concentration to areas of low concentration.  From MORE --> LESS.  Molecules such as salt, oxygen, calcium, wastes, etc.

Large molecules need help! Sometimes large molecules cannot cross the cell/plasma membrane,  "helped" across by carrier or channel proteins  this process is called facilitated diffusion

Osmosis  process by which WATER moves from areas of high concentration to areas of low concentration.  H 2 0 is VIP!  From MORE--> LESS  aka: osmosis is the “diffusion” of water

Osmosis animation *Water molecules are the small blue shapes. *Salt is the green.

Passive Transport This is the EASY way for substances to move.  The cell does not have to use any energy.  2 types: osmosis & diffusion

Active Transport Sometimes cells have to use or spend energy to get things across the cell membrane  Movement of materials from low concentration to higher concentration  Going against the concentration gradient  From LESS --> MORE

2 types of active transport Endocytosis - taking “in” Exocytosis - removing, “exiting”, taking out

Parts of a solution Solute - particle/substance that gets dissolved (solid) Solvent - substance that does the dissolving (liquid) solute + solvent = Solution

Salt is a solute ** when it is concentrated inside or outside the cell, it will draw the water in its direction. --> This is why you get thirsty after eating something salty.

3 types of solutions 1. ISOTONIC When the concentration of solute (salt) is equal on both sides water will move back & forth in equal amounts "ISO" means the same

2. HYPOTONIC When there is less solute (salt) molecules outside the cell, more water will move into the cell than moves out cell will gain water and grow larger, may burst!

3. HYPERTONIC When there are more solute (salt) molecules outside the cell, more water will move out of the cell than moves in cells lose so much water they will shrink! --> causes plants to wilt!