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Campbell Biology CH 7. Cell Membranes & Transport. Homeostasis. What is homeostasis? How is homeostasis maintained in living cells? Why is homeostasis needed in living cells? What cell components are involved in maintaining homeostasis?. Cell Membrane Function.
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Campbell Biology CH 7 Cell Membranes & Transport
Homeostasis • What is homeostasis? • How is homeostasis maintained in living cells? • Why is homeostasis needed in living cells? • What cell components are involved in maintaining homeostasis? U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Cell Membrane Function • What does a cell membrane do for the cell? • How does the cell membrane allow the cell to maintain homeostasis? • What does it mean to be selectively permeable? • How does the cell membrane regulate the passage of materials in and out of the cell? U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Cell Membrane: Lipid Bilayer U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Cell Membrane: Embedded Proteins U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Fluid Mosaic Model of CM U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Cell Membrane Fluidity • How is the cell membrane fluid? • What factors affect membrane fluidity? • What evolutionary adaptations do we see in membrane lipid composition? • Cold Water Fish • Thermophiles • Wheat • Human U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Cell Membrane Fluidity U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Cell Membrane Fluidity & Adaptation U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Cell Membrane: Proteins Types of Membrane Proteins Transmembrane Structure • Integral (Transmembrane) are found embedded in the lipid bilayer. • Peripheral are found on the surface of the lipid bilayer. U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Cell Membrane: Membrane Proteins U2-3 Describe the structure and function of cells, including organelles and cell membrane.
6 Main Functions Membrane Protein U2-3 Describe the structure and function of cells, including organelles and cell membrane.
6 Functions of Membrane Proteins U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Receptor Proteins & Cell Recognition Cell-Cell Recognition HIV Tricking Cell Receptors • Short carbohydrate chains covalently bonded to: • Lipids - Glycolipid • Proteins – Glycoprotein • Example: A, B, & O Blood Type Proteins U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Synthesis of Membrane Components U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Bozeman Science Cell Membrane • http://www.bozemanscience.com/015-cell-membrane U2-3 Describe the structure and function of cells, including organelles and cell membrane.
Transport: How Molecules Move Across the Cell Membrane U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Passive Transport = Diffusion Across Cell Membrane without Energy (ATP) • Diffusion of Molecules: • How do molecules diffuse? • From an area of high molecule concentration to an area of low molecule concentration. • Down the concentration gradient • Must be molecules that can pass through the lipid bilayer: Gases, Lipids, Small Molecules, Water • Paper Wad Diffusion Model U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Diffusion & Dynamic Equilibrium U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Diffusion & Dynamic Equilibrium U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Osmosis: Passive Diffusion of Water U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Water Balance In cells U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
A passive transport protein that changes shape to allow passage. • Carrier Protein • Channel Protein • Cotransporter • Ion Pump • Receptor Protein
A passive transport protein that with a pore for a molecule/ions to pass. • Carrier Protein • Channel Protein • Cotransporter • Ion Pump • Receptor Protein
The channel protein that regulates when molecules/ions pass. • Aquaporins • Ion Channels • Gated Channels
The channel protein that allows water to pass more rapidly. • Aquaporins • Ion Channels • Gated Channels
Facilitated Diffusion: Passive Transport with the Help of Proteins • Membrane proteins are specific to mlqs or ions & hydrophilic center • Channel Proteins: channel to pass through • Aquaporins (water) • Ion Channels • Gated Channels • Carrier Proteins: mlq binds, protein change shape, mlq moved to other side U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Active Transport require which of the following? • ATP • Membrane Proteins • Cellular Respiration • Photosynthesis • All of the above
The inside of a cell has a net positive charge. • True • False
A cation would need to be actively transported across the membrane to • Inside Cell • Outside Cell • Both • Neither
You can live when your cells reach electrical equilibrium. • True • False
Active Transport • Moving molecules/ions against the concentration gradient. • REQUIRES ATP!!! • Maintains Electrochemical Gradient • Moves other molecules using coupled transport U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Maintaining Electrical Potential Across the Cell Membrane • All cells MUST have a difference in charge across the cell membrane. • Inside Cell = Net Negative Charge • Outside Cell = Net Positive Charge • What would happen if charge was allowed to reach equilibrium? • There would be no charge difference. • YOU WOULD DIE!!! • Active transport maintains electrical potential. U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Proton Pump U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
With the sodium potassium ion • 2 Na+ pumped out & 3 K+ pumped in • 2 Na+ pumped in & 3 K+ pumped out • 3 Na+ pumped out & 2 K+ pumped in • 3 Na+ pumped in & 2 K+ pumped out
Sodium Potassium Pump U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Coupled Transport: Helping Other Molecules Move Across the Membrane U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Exocytosis = Exporting Larger Molecules/Waste U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Endocytosis: Importing Food U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Endocytosis: Importing Water U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport
Receptor-Mediated Endocytosis: Importing Specific Molecules U2-4 Explain how cells maintain homeostasis AND how substances move across a cell membrane using passive, active, and bulk transport