Cellular Transport In or Out 1 What are

Cellular Transport

In or Out? 1. What are some things that can pass through a window screen? 2. What are some things that can not pass through a window screen? Why is it important to keep these things from moving through the screen? 3. How is a window screen similar to a cell membrane? 4. Why is it important to regulate what moves into and out of the cell?

The Cell Membrane n Selectively permeable (semi-permeable) allows only certain substances to pass through cannot control the movement of water Cell membrane

The Cell Membrane Double layer of lipids with proteins scattered throughout Protein Carbohydrate chain Lipid bilayer Hydrophilic head hydrophobic tail Protein

The Cell Membrane n The cell membrane helps to maintain homeostasis n Homeostasis- maintaining a stable internal environment even though external conditions change

Passive Transport n n No energy is required Diffusion, Osmosis, and facilitated diffusion are types of passive transport

Diffusion n Particles move from an area of high concentration to an area of low concentration Moves “down” or “with” the concentration gradient Does NOT require energy http: //highered. mcgrawhill. com/sites/0072495855/student _view 0/chapter 2/animation__how_ diffusion_works. html

Diffusion n Factors effecting the rate of diffusion 1. temperature (as temp increases rate increases) 2. pressure (as pressure increases rate increases) 3. steepness of the concentration gradient (the steeper the gradient the faster the diffusion)

Osmosis n Movement of WATER across a cell membrane

Water always moves toward the higher concentration of solute particles

Types of Solutions n Isotonic n Hypertonic

Types of Solutions n Isotonic – solutes inside = solutes outside n Hypotonic – solutes are higher inside the cell n n n water flows in, cell swells cell could burst if continues Hypertonic – solutes are higher outside the cell n water leaves cell, cell shrinks

Types of Solutions Isotonic Hypotonic Water particle Solute particle Hypertonic

Types of Solutions Effects on Animal Cells http: //www. nclar k. net/osmosis. Poc us. gif The pictures below are red blood cells in different concentrations of salt solution. Identify which pictures are hypotonic, isotonic, and hypertonic solutions. Isotonic Hypertonic Hypotonic

Types of Solutions Effects on Plant Cells Which of these cells are in a hypotonic solution? Hypertonic solution? Hypotonic Hypertonic Onion cells plasmolysis http: //www. youtube. com/watch? v=Soo. Ss. Kk. Jo 1 o

Types of Solutions Effects on Plant Cells n Turgor pressure. Plant cells fill with water and press against the cell walls making the cells rigid

Types of Solutions Effects on Animal Cells n n Contractile Vacuolesstructure in protists that collects and expels excess water out of the cell to prevent the cell from exploding (lysing) http: //www. youtube. com/watch? v=i. G 6 D d 3 COug 4

Facilitated diffusion n n Facilitated diffusion occurs when molecules move from an area of high concentration to an area of low concentration with the aid of a protein molecule Does not require energy http: //highered. mcgrawhill. com/sites/0072495855/student_vi ew 0/chapter 2/animation__how_facili tated_diffusion_works. html

Active Transport n n n Requires energy moves from an area of low concentration to an area of high concentration moves “up” or “against” the concentration gradient

Active Transport LOW HIGH ENERGY FROM ATP PUSHES MOLECULES ACROSS THE MEMBRANE

WATCH ACTIVE TRANSPORT LOW TO HIGH ENERGY NEEDED

Active Transport http: //highered. mcgrawhill. com/sites/0072495855/student_view 0/chapter 2/animati on__how_the_sodium_potassium_pump_works. html

Bulk Transport n n Sometimes the size of the particle or the amount that needs to be moved through the membrane is too large. Then bulk transport is used

Bulk Transport n n Sometimes the size of the particle or the amount that needs to be moved through the membrane is too large. Then Bulk transport is used

Bulk Transport n n Endocytosis- movement into a cell by forming a vacuole around the particles. Exocytosis- movement out of a cell by releasing the contents of a vacuole.

Bulk Transport Endocytosis Exocytosis

Bulk Transport n n Pinocytosis- movement of large volumes of solution with dissolved solutes in or out of the cell Phagocytosis- movement of large particles into or out of the cell

Bulk Transport n n An amoeba feeds on a Paramecium http: //www. youtube. com/watch? v=W 6 rnhi. Mxt. KU&fe ature=player_embedded