Do Now! Copy vocabulary words into your notebooks: cell membrane concentration diffusion osmosis equilibrium active transport passive transport

Cell Membrane Controls what enters and exits the cell Lipid bilayer Hydrophilic heads (water loving) are on the outsides of the membrane Hydrophobic tails (water fearing) are in the inside of the membrane Have protein channels embedded through out the membrane that act like doors to let large molecules in and out

Concentration Not what this means in science This is what we want The amount of a substance in an area

DIFFUSION: the movement of molecules from an area of high to low concentration – DOES NOT REQUIRE ENERGY

Passive Transport Does osmosis or diffusion require energy? No, molecules move along a concentration gradient.

Facilitated Diffusion Facilitated Diffusion- molecules move down a concentration gradient with the aid of special proteins.

Osmosis The movement of water across a semipermeable membrane like the cell membrane. Water wants to balance out each side of the membrane Equilibrium – everything is balanced

3 types of solutions Iso – equal Hypo – below Hyper - above Remember water wants to equal everything out so it will move in the direction there is less water and more solutes.

Solutions

Solutions in Plants

Active Transport Requires Energy. ATP (form of energy made by mitochondria). Moves against the concentration gradient.

Endocytosis Transporting material into a cell by the in folding of a membrane.

2 Types of Endocytosis Phagocytosis- Solid particles are ingested into the cell. Pinocytosis – liquids taken into the cell.

Exocytosis Moves materials out of the cell

Summary What is Diffusion? What is Osmosis? What is Active Transport? What is Passive Transport?