+ Cellular Transport Bio Explain how homeostasis is maintained in a cell and within an organism in various environments (including temperature and pH).

+ What is the cell membrane used for? 1. Controls what enters and exits the cell 2. Maintains an internal balance AKA: Homeostasis 3. Provides protection 4. Provides support

+ Can you recall the structure of the Cell membrane? Phospholipid Bilayer : A Bicycle has 2 wheels VS Bilayer has two layers!

+ Phospholipid Bilayer consist of: 1. Phosphate Head (polar)( hydro philic) 2. Fatty Acid Tail (non-polar) ( hydro phobic) 3. Embedded Proteins

+ Draw a Phosphate head and a fatty acid tail Label: Head Tail Hydrophobic Hydrophilic

+ Does the Cell membrane allow anything to come into the cell? Selectively permeable: Allows some molecules in and keeps other molecules out gy_place/biocoach/biomembrane1/per meability.html gy_place/biocoach/biomembrane1/per meability.html

+ 2 Types of Cellular Transport 1.Passive : no energy used by the cell Diffusion Facilitated Diffusion Osmosis (High to Low) 2. Active : Energy used by the cell Protein Pumps Endocytosis Exocytosis (Low to High)

+ Low to high (so much slower) lots of energy used High to Low (so much faster) No energy used

+ Passive Transport no energy used molecules move randomly Molecules spread out from an area of high concentration to an area of low concentration. (High  Low)

+ 3 types of Passive Transport 1. Diffusion 2. Facilitative Diffusion 3. Osmosis

+ Diffusion random movement of particles from an area of high concentration to an area of low concentration. continues until all molecules are evenly spaced

+ Facilitative Diffusion. Facilitated diffusion: diffusion of specific particles through transport proteins found in the membrane a. Transport Proteins are specific – they “select” only certain molecules to cross the membrane b. Transports larger or charged molecules

+ Osmosis Osmosis: diffusion of water through a selectively permeable membrane Water moves from high to low concentrations Water is small and there is a lot of it. The cell can not control it’s movement through the cell membrane q3hOgC8YE

+ 3 types of Active Transport Protein Pumps Endocytosis Exocytosis

+ Active Transport cell uses energy actively moves molecules to where they are needed Movement from an area of low concentration to an area of high concentration

+ Type of Active Transport Protein Pumps -transport proteins ( needs energy AKA ATP to do work) PUMPS material into the cell

+ Type of Active Transport Endocytosis: taking large material into a cell Uses energy “cell eating” forms food vacuole & digests food This is how white blood cells eat bacteria

+ Endocytosis

+ Type of Active Transport Exocytosis : Forces material out of cell in bulk membrane surrounding the material fuses with cell membrane Cell changes shape – uses energy Example: Hormones or wastes released from cell

+ Cell must maintain their pH This is done by using Buffers :molecules that easily interconvert between acidic and basic forms, donating or accepting protons as conditions change. HOMEOSTASIS

+ Can you recall Turgor Pressure? The PRESSURE exerted by WATER inside the cell against the CELL WALL

+ Solutes vs. Solution (solvent) Solution: Mixture of one or more substance (solutes) are distributed evenly in another substances (solvent). WHAT IS THE UNIVERSAL SOLVENT? Solutes: Is mixed into the solvent ( sugar or salt) LETS SEE THIS

+ Keep in mind SOLUTES SUCK High to Low

+ LET’S TALK ABOUT HYPER,HYPO AND ISO!

+ Hypertonic The solution has a higher concentration of solutes 20% and a lower concentration of water than inside the cell. (High solute to Low water)

+ Hypotonic The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute to High water)

+ Isotonic The concentration of solutes in the solution is equal to the concentration of solutes inside the cell.

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