CELLS Diffusion

Diffusion

Movement across membrane from high to low concentration

Concentration gradient

How concentrated something is

Passive transport

Cell doesn’t need to expend energy to move stuff across membrane

Osmosis

Water movement across semi-permeable membrane

Tonicity

Ability of a solution to cause a cell to gain or lose water

Hypertonic

If a cell is in this environment, it loses water and shrivels up

Plants: Plasmolysis (cell loses water, plasma breaks off of cell wall and shrivels up)

Isotonic

If a cell is in this environment, the net movement of water is 0

Animals: Good for them, natural state

Plants: Flaccid (limp) state, ba

Hypotonic

If a cell is in this environment, net water movement is into the cell so it expands.

Animals: Cell bursts

Plants: Turgid (very firm), best state for plants

Facilitated Diffusion

Transport proteins live in the phospholipid bilayer membrane, 2 kinds: channel and carrier proteins

Channel proteins (type 1 of Facilitated Diffusion)