I went into a cell, to get out of the rain… and what did I see?… and said “who drives this bus?”… to recover from a spasm… … _________________. … __________________. … ___________________.

…___________________. I went into the nucleus, to ask how to get home… I went into a cell, and stretching oh so far… Trying not to be perplexed… And said “who makes proteins here?”… …___________________. …__________________. …____________________.

…___________________. I went into a cell, and was feeling pretty fine… and was feeling pretty nimble… I went into a plant cell, to see how trees get so tall… “why’s it green I asked?”… …___________________. …__________________. …____________________.

I went into a plant cell, to see plant cells store food… So when you go inside a cell… Just sing this song if you ever feel confusion… …_______________.

Chpt. 5 HOMEOSTASIS & TRANSPORT cells regulate the movement of materials across their membranes maintain internal balance despite changes in their environment This happens in ways that either DON’T REQUIRE ENERGY DO REQUIRE ENERGY

PASSIVE TRANSPORT Uses NO ENERGY Molecules move DOWN or “with” their concentration gradient. [HIGH]  [LOW] 1. Diffusion 2. Osmosis 3. Facilitated Diffusion ACTIVE TRANSPORT Uses ENERGY Molecules move UP or “against” their concentration gradient. [LOW]  [HIGH] 1. Pump 2. Endocytosis 3. Exocytosis

PASSIVE TRANSPORT Molecules move down their concentration gradient across a membrane. High Concentration -> Low Concentration. No ATP energy required. Ex. Oxygen into your cells from your bloodstream, Carbon dioxide out of your cells to your bloodstream.

ACTIVE TRANSPORT Molecules move across the membrane against their concentration gradient. Low Concentration -> High Concentration. Requires ATP energy. Ex. Fructose into plant cells of a fruit.

DIFFUSION Movement of molecules from an area of high concentration to an area of low concentration.

What molecules diffuse through/ across the cell membrane? Oxygen & Carbon Dioxide go through the phospholipid bilayer. Others must go through the protein channels.

OSMOSIS- the diffusion of water Diffusion of water through a selectively permeable membrane. Water moves through a membrane from an area of high water concentration to an area of low water concentration.

TONICITY- term used to compare the solute concentrations of two solutions and predict the osmotic flow of water between them. Isotonic- same Hypertonic- more solute & less water Hypotonic- Less solute & more water Water always flows from the hypOtonic to the hypertonic.

WHAT HAPPENS IF YOU PUT A CELL INTO A ____ SOLUTION? HYPERTONIC HYPOTONIC ISOTONIC swell Stay same shrivel

WHAT HAPPENS IF YOU PUT A CELL INTO A ____ SOLUTION? HYPOTONIC ISOTONIC HYPERTONIC swell Stay same shrivel

PASSIVE TRANSPORT Diffusion through phospholipid bilayer ex. O2 & CO2 Osmosis is the diffusion of water

Facilitated Diffusion - uses carrier proteins because the molecule has a charge & is too big to fit through the bilayer. Ex. glucose & amino acids

Diffusion through Ion Channels- charged small molecules or ions travel through membrane protein tunnels Ex. -Na+, Cl-, K+, H2O (aquaporins)

ACTIVE TRANSPORT Cell membrane pump- Uses carrier protein. Moves materials up or AGAINST their concentration gradient. Ex. Sodium-potassium pump in animals or the hydrogen pump in plants. Na+ out K+ in 1 ATP 1 ATP 1 H+ in

ex. Pinocytosis (drink) Liquids & small solutes & Phagocytosis (eat) 2. Endocytosis- Process by which cells ingest external fluid, macromolecules, and large proteins, & other cells! ex. Pinocytosis (drink) Liquids & small solutes & Phagocytosis (eat) Smaller cells or large organic molecules.

3.Exocytosis- the reverse of endocytosis. Release proteins made on ribosomes and modified in the golgi apparatus.