Wednesday September 20, 2017 Bell Ringer Copy and answer the following: What is homeostasis? Why is it important for the cell membrane to guard what enters and leaves the cell?
copyright cmassengale Amoeba Sisters Video copyright cmassengale
Thursday September 21, 2017 Bell Ringer Copy and answer the following: 1. What process was being used by the “cells” in yesterday’s lab? 2. Sketch a picture that shows how the vinegar moved in the experiment. copyright cmassengale
copyright cmassengale The Plasma Membrane 2/16/2019 The Plasma Membrane - Gateway to the Cell copyright cmassengale G. Podgorski, Biol. 1010
Photograph of a Cell Membrane The Plasma Membrane 2/16/2019 Photograph of a Cell Membrane copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Cell Membrane The cell membrane is flexible and allows a unicellular organism to move copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Homeostasis Balanced internal condition of cells Also called equilibrium Maintained by plasma membrane controlling what enters & leaves the cell copyright cmassengale G. Podgorski, Biol. 1010
Functions of Plasma Membrane The Plasma Membrane 2/16/2019 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
Functions of Plasma Membrane The Plasma Membrane 2/16/2019 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
Structure of the Cell Membrane The Plasma Membrane 2/16/2019 Structure of the Cell Membrane copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale Membrane Components The Plasma Membrane 2/16/2019 Phospholipids Proteins (peripheral and integral) Cholesterol copyright cmassengale Carbohydrates (glucose) G. Podgorski, Biol. 1010
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copyright cmassengale The Plasma Membrane 2/16/2019 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
copyright cmassengale The Plasma Membrane 2/16/2019 FLUID MOSAIC MODEL FLUID- because individual phospholipids and proteins can move side-to-side within the layer, like it’s a liquid. MOSAIC- because of the pattern produced by the scattered protein molecules when the membrane is viewed from above. copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane Cell Membrane 2/16/2019 Polar heads are hydrophilic “water loving” Nonpolar tails are hydrophobic “water fearing” Makes membrane “Selective” in what crosses copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane Cell Membrane 2/16/2019 The cell membrane is made of 2 layers of phospholipids called the lipid bilayer Hydrophobic molecules pass easily; hydrophilic DO NOT copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Solubility Materials that are soluble in lipids can pass through the cell membrane easily copyright cmassengale G. Podgorski, Biol. 1010
Semipermeable Membrane The Plasma Membrane Semipermeable Membrane 2/16/2019 Small molecules and larger hydrophobic molecules move through easily. e.g. O2, CO2, H2O copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane Semipermeable Membrane 2/16/2019 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
Friday September 22, 2017 Bell Ringer Copy and answer: Based on the cell membrane activity yesterday, why do phospholipids form a bilayer in a cell membrane? Make sure to include the words polar, nonpolar, hydrophilic and hydrophobic. copyright cmassengale
Types of Transport Across Cell Membranes The Plasma Membrane 2/16/2019 Types of Transport Across Cell Membranes copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Simple Diffusion Requires NO energy Molecules move from area of HIGH to LOW concentration copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 DIFFUSION Diffusion is a PASSIVE process which means no energy is used to make the molecules move, they have a natural KINETIC ENERGY copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Diffusion of Liquids copyright cmassengale G. Podgorski, Biol. 1010
Diffusion through a Membrane The Plasma Membrane 2/16/2019 Diffusion through a Membrane Cell membrane Solute moves DOWN concentration gradient (HIGH to LOW) copyright cmassengale G. Podgorski, Biol. 1010
Diffusion across a membrane Semipermeable membrane The Plasma Membrane 2/16/2019 Osmosis Diffusion across a membrane Diffusion of water across a membrane Moves from HIGH water potential (low solute) to LOW water potential (high solute) Semipermeable membrane copyright cmassengale G. Podgorski, Biol. 1010
Diffusion of H2O Across A Membrane The Plasma Membrane 2/16/2019 Diffusion of H2O Across A Membrane High H2O potential Low solute concentration Low H2O potential High solute concentration copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Aquaporins Water Channels Protein pores used during OSMOSIS WATER MOLECULES copyright cmassengale G. Podgorski, Biol. 1010
Cell in Isotonic Solution The Plasma Membrane 2/16/2019 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 _______________. copyright cmassengale G. Podgorski, Biol. 1010
Cell in Hypotonic Solution The Plasma Membrane 2/16/2019 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
Cell in Hypertonic Solution The Plasma Membrane 2/16/2019 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
copyright cmassengale The Plasma Membrane 2/16/2019 Cells in Solutions copyright cmassengale G. Podgorski, Biol. 1010
NO NET MOVEMENT OF H2O (equal amounts entering & leaving) The Plasma Membrane 2/16/2019 Isotonic Solution Hypotonic Solution Hypertonic Solution NO NET MOVEMENT OF H2O (equal amounts entering & leaving) CYTOLYSIS PLASMOLYSIS copyright cmassengale G. Podgorski, Biol. 1010
Cytolysis & Plasmolysis The Plasma Membrane 2/16/2019 Cytolysis & Plasmolysis copyright cmassengale Cytolysis Plasmolysis G. Podgorski, Biol. 1010
Osmosis in Red Blood Cells The Plasma Membrane 2/16/2019 Osmosis in Red Blood Cells Isotonic Hypertonic Hypotonic copyright cmassengale G. Podgorski, Biol. 1010
What Happens to Blood Cells? copyright cmassengale
copyright cmassengale The Plasma Membrane 2/16/2019 isotonic hypotonic hypertonic hypertonic isotonic hypotonic copyright cmassengale G. Podgorski, Biol. 1010
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Thursday September 17, 2015 Bell Ringer Copy and answer the following: If a blood cell were to be placed in an isotonic solution, what would happen to the size of the cell? What would happen to the size of a cell if it were placed into a hypertonic solution?
Friday September 18, 2015 Bell Ringer The Plasma Membrane 2/16/2019 Friday September 18, 2015 Bell Ringer Answer the following questions: What do you think is happening in the picture? Do you think that the cell is using energy in the drawing? copyright cmassengale G. Podgorski, Biol. 1010
Three Forms of Transport Across the Membrane The Plasma Membrane Three Forms of Transport Across the Membrane 2/16/2019 copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Passive Transport 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
Facilitated diffusion The Plasma Membrane 2/16/2019 Passive Transport Facilitated diffusion Doesn’t require energy Uses transport proteins to move high to low concentration Examples: Glucose or amino acids moving from blood into a cell. copyright cmassengale G. Podgorski, Biol. 1010
Proteins Are Critical to Membrane Function The Plasma Membrane 2/16/2019 Proteins Are Critical to Membrane Function copyright cmassengale G. Podgorski, Biol. 1010
Types of Transport Proteins The Plasma Membrane 2/16/2019 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
Facilitated Diffusion The Plasma Membrane 2/16/2019 Facilitated Diffusion Molecules will randomly move through the pores in Channel Proteins. copyright cmassengale G. Podgorski, Biol. 1010
Facilitated Diffusion The Plasma Membrane 2/16/2019 Facilitated Diffusion Some Carrier proteins do not extend through the membrane. They bond and drag molecules through the lipid bilayer and release them on the opposite side. copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Carrier Proteins Other carrier proteins change shape to move materials across the cell membrane copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Active Transport Requires energy or ATP Moves materials from LOW to HIGH concentration AGAINST concentration gradient copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Active transport Examples: Pumping Na+ (sodium ions) out and K+ (potassium ions) in against strong concentration gradients. Called Na+-K+ Pump copyright cmassengale G. Podgorski, Biol. 1010
Sodium-Potassium Pump The Plasma Membrane 2/16/2019 Sodium-Potassium Pump 3 Na+ pumped in for every 2 K+ pumped out; creates a membrane potential copyright cmassengale G. Podgorski, Biol. 1010
Moving the “Big Stuff” Exocytosis- moving things out. The Plasma Membrane Moving the “Big Stuff” 2/16/2019 Exocytosis- moving things out. Molecules are moved out of the cell by vesicles that fuse with the plasma membrane. This is how many hormones are secreted and how nerve cells communicate with one another. copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane Exocytosis 2/16/2019 Exocytic vesicle immediately after fusion with plasma membrane. copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane Moving the “Big Stuff” 2/16/2019 Large molecules move materials into the cell by one of three forms of endocytosis. copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane Pinocytosis 2/16/2019 Most common form of endocytosis. Takes in dissolved molecules as a vesicle. copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Pinocytosis Cell forms an invagination Materials dissolve in water to be brought into cell Called “Cell Drinking” copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane Example of Pinocytosis 2/16/2019 mature transport vesicle pinocytic vesicles forming copyright cmassengale Transport across a capillary cell (blue). G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Receptor-Mediated Endocytosis Some integral proteins have receptors on their surface to recognize & take in hormones, cholesterol, etc. copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane Receptor-Mediated Endocytosis 2/16/2019 copyright cmassengale G. Podgorski, Biol. 1010
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copyright cmassengale The Plasma Membrane 2/16/2019 Endocytosis – Phagocytosis Used to engulf large particles such as food, bacteria, etc. into vesicles Called “Cell Eating” copyright cmassengale G. Podgorski, Biol. 1010
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copyright cmassengale The Plasma Membrane Phagocytosis About to Occur 2/16/2019 copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Phagocytosis - Capture of a Yeast Cell (yellow) by Membrane Extensions of an Immune System Cell (blue) copyright cmassengale G. Podgorski, Biol. 1010
copyright cmassengale The Plasma Membrane 2/16/2019 Exocytosis The opposite of endocytosis is exocytosis. Large molecules that are manufactured in the cell are released through the cell membrane. Inside Cell copyright cmassengale Cell environment G. Podgorski, Biol. 1010
Thursday February 9, 2017 Bell Ringer Answer the following question: The experimental setup shows an osmometer. An osmometer is a device used to measure the amount of osmotic pressure exerted by a liquid passing through a semipermeable membrane. The graph shows one lab group’s results compared with the results of the rest of the class combined. Line A represents the results of the single lab group. Line B represents the data of the rest of the class. Predict Look at the graph in Figure 7–12. How would the results differ if a sucrose solution with twice the concentration of the one used to collect the results represented by line A were used? copyright cmassengale