Cellular Transport Yeast cells stained with fluorescent dye The cell membrane

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

The fluid mosaic model double layer of lipids with proteins scattered throughout flexible, phospholipids move with in the membrane

Parts of the cell membrane Phospholipids lipids with a phosphate group attached to one end makes molecule polar so it can react with water

Parts of the Cell Membrane Transport Proteins- allows needed substances or waste materials through membrane

Parts of the Cell Membrane Cholesterol stabilizes the phospholipids does not allow fatty acid chains to stick together cholesterol

Things Must Go In, Things Must Come Out - Transport 1. Passive Transport Active Transport

Three Types: Diffusion, Osmosis, and Facilitated Diffusion Passive Transport NO energy required Moves with the Concentration Gradient Three Types: Diffusion, Osmosis, and Facilitated Diffusion

Diffusion 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

Diffusion 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) http://science.nhmccd.edu/biol/bio1int.htm#transport

Osmosis Movement of WATER across a cell membrane Cell has no control continues to move until [inside] = [outside] called dynamic equilibrium [ ]- means “the concentration of”

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

Types of Solutions Isotonic Hypotonic Hypertonic Water particle Solute particle

Types of Solutions Water always moves toward the solution with the highest concentration of solute. Highest concentration of solute means the lowest concentration of water.

Types of Solutions Effects on Animal Cells 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 http://ccollege.hccs.edu/instru/Biology/AllStudyPages/Diffusion_Osmosis/Elodeagif.swf

Words to Know Turgor Pressure – Pressure placed against the cell wall by the cell membrane. Provides the plant support (hold the plant up). Plasmolysis – Cell Membrane moves away from the cell wall as water moves out of the cell, causes the plant to wilt. Contractile Vacuole – Found in unicellular organisms with a cell membrane (no cell wall), helps to pump out water as it moves into the organism.

Facilitated Diffusion http://www.wisc-online.com/objects/index_tj.asp?objID=AP11103 Facilitated Diffusion Moves down the concentration gradient with help of carrier proteins Does not use energy, because still moves with the concentration gradient Most glucose moves this way

Active Transport Requires energy moves from an area of low concentration to an area of high concentration moves “up” or “against” the concentration gradient glucose moved from blood stream into liver for storage

http://www.wisc-online.com/objects/index_tj.asp?objID=AP11203 Active Transport http://programs.northlandcollege.edu/biology/Biology1111/animations/transport1.html

Moving large particles across the cell membrane Endocytosis – movement of large particles into the cell Exocytosis – movement of large particles out of the cell Endocytosis Exocytosis

Phagocytosis and Pinocytosis Types of Endocytosis Phagocytosis - Eating Pinocytosis - Drinking