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Create your Unit 3: Cell Transport Cover page
Bellringer: 10/16/17 Create your Unit 3: Cell Transport Cover page copyright cmassengale
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The Plasma Membrane 7/3/2018 The Plasma Membrane - Gateway to the Cell copyright cmassengale G. Podgorski, Biol. 1010
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Photograph of a Cell Membrane
The Plasma Membrane 7/3/2018 Photograph of a Cell Membrane copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 Homeostasis Balanced internal condition of cells (Equilibrium) Maintained by plasma membrane controlling what enters & leaves the cell copyright cmassengale G. Podgorski, Biol. 1010
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Functions of Plasma Membrane
The Plasma Membrane 7/3/2018 Functions of Plasma Membrane Protective barrier Regulate transport in & out of cell (selectively permeable) Allow cell recognition Provide anchoring sites for filaments of cytoskeleton copyright cmassengale G. Podgorski, Biol. 1010
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Functions of Plasma Membrane
The Plasma Membrane 7/3/2018 Functions of Plasma Membrane Provide a binding site for enzymes Interlocking surfaces bind cells together (junctions) Contains the cytoplasm (fluid in cell) copyright cmassengale G. Podgorski, Biol. 1010
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Structure of the Cell Membrane
The Plasma Membrane 7/3/2018 Structure of the Cell Membrane copyright cmassengale G. Podgorski, Biol. 1010
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Membrane Components Phospholipids Proteins (peripheral and integral)
The Plasma Membrane 7/3/2018 Phospholipids Proteins (peripheral and integral) Cholesterol Carbohydrates (glucose) G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 FLUID MOSAIC MODEL FLUID- because individual phospholipids and proteins can move side-to-side within the layer MOSAIC- because scattered protein molecules form a pattern when the membrane is viewed from above G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 Phospholipids Make up the cell membrane Contains 2 fatty acid chains that are nonpolar Head is polar & contains a –PO4 group & glycerol copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane Cell Membrane 7/3/2018 The cell membrane is made of 2 layers of phospholipids called the phospholipid bilayer copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane Cell Membrane 7/3/2018 Orientation of the phospholipid layers makes membrane “Selective” in what crosses Hydrophobic molecules pass easily Hydrophilic molecules DO NOT G. Podgorski, Biol. 1010
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Semipermeable Membrane
The Plasma Membrane Semipermeable Membrane 7/3/2018 Small molecules and larger hydrophobic molecules move through easily (although slowly). e.g. O2, CO2, H2O copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane Semipermeable Membrane 7/3/2018 Ions, hydrophilic molecules larger than water, and large molecules such as proteins do not move through the membrane on their own. copyright cmassengale G. Podgorski, Biol. 1010
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Proteins Are Critical to Membrane Function
The Plasma Membrane 7/3/2018 Proteins Are Critical to Membrane Function copyright cmassengale G. Podgorski, Biol. 1010
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Types of Transport Proteins
The Plasma Membrane 7/3/2018 Types of Transport Proteins Channel proteins are embedded in the cell membrane & have a pore for materials to cross Carrier proteins can change shape to move material from one side of the membrane to the other copyright cmassengale G. Podgorski, Biol. 1010
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Types of Transport Across Cell Membranes
The Plasma Membrane 7/3/2018 Types of Transport Across Cell Membranes copyright cmassengale G. Podgorski, Biol. 1010
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Three Forms of Transport Across the Membrane
The Plasma Membrane Three Forms of Transport Across the Membrane 7/3/2018 G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 Passive Transport 1. Simple Diffusion Doesn’t require energy Moves high to low concentration Example: Oxygen or water diffusing into a cell and carbon dioxide diffusing out. copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 Diffusion of Liquids copyright cmassengale G. Podgorski, Biol. 1010
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Diffusion through a Membrane
The Plasma Membrane 7/3/2018 Diffusion through a Membrane Cell membrane Solute moves DOWN concentration gradient (HIGH to LOW) G. Podgorski, Biol. 1010
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2. Facilitated diffusion
The Plasma Membrane 7/3/2018 Passive Transport 2. Facilitated diffusion Doesn’t require energy Uses transport proteins to move high to low concentration because large molecules Examples: Glucose or amino acids moving from blood into a cell. G. Podgorski, Biol. 1010
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Facilitated Diffusion
The Plasma Membrane 7/3/2018 Facilitated Diffusion Molecules will randomly move through the pores in Channel Proteins. copyright cmassengale G. Podgorski, Biol. 1010
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Bellringer 10/17/16 Draw the following data on the left side of your lab
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Day 1 Post-Lab Questions
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Warm up Draw a diagram of a cell membrane. Include phospholipids, membrane protein channels, and small polar particles moving across the membrane. copyright cmassengale
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Day 2 Post-Lab Questions
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Day 2 Post-lab Continued
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Warm Up Describe the characteristics of the head and tail of a phospholipid. Which type of molecules can easily pass through a cell membrane? copyright cmassengale
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Diffusion across a membrane Semipermeable membrane
The Plasma Membrane 7/3/2018 Osmosis Diffusion across a membrane Diffusion of water across a membrane Moves from HIGH water (low solute) to LOW water (high solute) Water attempts to dilute highly concentrated solutions Semipermeable membrane copyright cmassengale G. Podgorski, Biol. 1010
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Diffusion of H2O Across A Membrane
The Plasma Membrane 7/3/2018 Diffusion of H2O Across A Membrane High H2O Low solute concentration Low H2O High solute concentration G. Podgorski, Biol. 1010
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Aquaporins Water Channels Protein pores used during OSMOSIS
The Plasma Membrane 7/3/2018 Aquaporins Water Channels Protein pores used during OSMOSIS WATER MOLECULES G. Podgorski, Biol. 1010
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Osmoregulation Maintenance of constant osmotic pressure in fluids of an organism Control of water and salt concentrations Helps maintain homeostasis Movement of water and salt is dependent on tonicity copyright cmassengale
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Tonicity Hypotonic solution – the solution has lower solute concentration than the cell Hypertonic solution – the solution has higher solute concentration than the cell Isotonic solution – the concentration of solution and cell are equal copyright cmassengale
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Cell in Hypotonic Solution
The Plasma Membrane 7/3/2018 Cell in Hypotonic Solution 10% NaCL 90% H2O CELL 20% NaCL 80% H2O What is the direction of water movement? copyright cmassengale G. Podgorski, Biol. 1010
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Cell in Hypertonic Solution
The Plasma Membrane 7/3/2018 Cell in Hypertonic Solution 15% NaCL 85% H2O ENVIRONMENT CELL 5% NaCL 95% H2O What is the direction of water movement? copyright cmassengale G. Podgorski, Biol. 1010
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Cell in Isotonic Solution
The Plasma Membrane 7/3/2018 Cell in Isotonic Solution 10% NaCL 90% H2O ENVIRONMENT CELL NO NET MOVEMENT 10% NaCL 90% H2O What is the direction of water movement? equilibrium The cell is at _______________. G. Podgorski, Biol. 1010
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NO NET MOVEMENT OF H2O (equal amounts entering & leaving)
The Plasma Membrane 7/3/2018 Isotonic Solution Hypotonic Solution Hypertonic Solution NO NET MOVEMENT OF H2O (equal amounts entering & leaving) CYTOLYSIS PLASMOLYSIS copyright cmassengale G. Podgorski, Biol. 1010
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Cytolysis & Plasmolysis
The Plasma Membrane 7/3/2018 Cytolysis & Plasmolysis copyright cmassengale Cytolysis Plasmolysis G. Podgorski, Biol. 1010
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Osmosis in Red Blood Cells
The Plasma Membrane 7/3/2018 Osmosis in Red Blood Cells Isotonic Hypertonic Hypotonic copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 isotonic hypotonic hypertonic hypertonic isotonic hypotonic copyright cmassengale G. Podgorski, Biol. 1010
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Warm-Up 10/31/16 HAPPY HALLOWEEN!! Predict which type of transport would be used to move the following particles across the membrane. (diffusion, facilitated diffusion or active transport)? Water B. oxygen (O2) C. Glucose (C6H12O6) D. Na+ E. CO2 copyright cmassengale
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The Plasma Membrane 7/3/2018 3. Active Transport Requires energy or ATP Moves materials from LOW to HIGH concentration AGAINST concentration gradient copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 Active transport Examples: Pumping Na+ out and K+ in against strong concentration gradients Called Na+/K+ Pump Essential in your nerve cells copyright cmassengale G. Podgorski, Biol. 1010
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Sodium-Potassium Pump
The Plasma Membrane 7/3/2018 Sodium-Potassium Pump 3 Na+ pumped in for every 2 K+ pumped out; creates a membrane potential G. Podgorski, Biol. 1010
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The Plasma Membrane Moving the “Big Stuff” 7/3/2018 Large molecules move materials into the cell by one of two forms of endocytosis. copyright cmassengale G. Podgorski, Biol. 1010
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Pinocytosis Most common form of endocytosis
The Plasma Membrane Pinocytosis 7/3/2018 Most common form of endocytosis “Cell drinking” because takes in dissolved molecules as a vesicle G. Podgorski, Biol. 1010
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The Plasma Membrane Example of Pinocytosis 7/3/2018 mature transport vesicle pinocytic vesicles forming copyright cmassengale Transport across a capillary cell (blue). G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 Phagocytosis Used to engulf large particles such as food, bacteria, etc. into vesicles Called “Cell Eating” G. Podgorski, Biol. 1010
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The Plasma Membrane Phagocytosis About to Occur 7/3/2018 copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 Phagocytosis - Capture of a Yeast Cell (yellow) by Membrane Extensions of an Immune System Cell (blue) copyright cmassengale G. Podgorski, Biol. 1010
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The Plasma Membrane 7/3/2018 Exocytosis The opposite of endocytosis is exocytosis. Large molecules are transported in vesicles that fuse with the cell membrane and release contents outside Inside Cell copyright cmassengale Cell environment G. Podgorski, Biol. 1010
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The Plasma Membrane Moving the “Big Stuff” 7/3/2018 Ex. Secretion of hormones; nerve cells communicating with each other G. Podgorski, Biol. 1010
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The Plasma Membrane Exocytosis 7/3/2018 Exocytic vesicle immediately after fusion with plasma membrane. copyright cmassengale G. Podgorski, Biol. 1010
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Transport across a Membrane
Small molecules Simple diffusion (i.e. osmosis) Facilitated diffusion (needs channel) Active transport (needs channel and energy) Large molecules/large quantities Endocytosis Pinocytosis (drinking) Phagocytosis (eating) Exocytosis copyright cmassengale
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