Physiology 168 March 14‚ 2014 Diffusion across a Selectively Permeable membrane Introduction: Diffusion is movement of molecules from one area of concentration to another. This process is vital for the life functions of cells. Cells have selectively permeable membranes that allow only certain solutions to pass through them. Osmosis is a special kind of diffusion that allows water to go through semi-permeable membranes of high water potential to a region of lower water potential. Water potential
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The cell membrane is made up of fats‚ proteins‚ lipids‚ and carbohydrates‚ and is a permeable structure. However‚ this permeation is very discerning because it only lets certain things pass through it. The cell membrane has a layer of phospholipids with hydrophobic ends and hydrophilic tops. The “tails” are made out of phosphate‚ while the “heads” are made up of two strings of fatty acids. There are two layers of these phospholipids‚ called the “bilayer”‚ and the tips of each phospholipid are facing
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Cell Membrane and Organelle Webquest Name Yamani Woody Using the websites listed‚ answer the following questions. Website #1: http://www.usd.edu/~bgoodman/Membrane.htm http://www.biologymad.com/cells/cellmembrane.htm 1. What invention came along that enabled us to better see the cell membrane? Electron Microscope 2. What are the two parts (list the first two listed) of the cell membrane? Phospholipids and proteins 3. What is one of the cell membrane’s jobs? It controls how substances can
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The plasma membrane surrounds the cytoplasm of living cells‚ physically separating the intracellular components from the extracellular environment. It also plays a role in anchoring the cytoskeleton provide shape to the cell‚ and in attaching to the extracellular matrix and other cells to help group cells together to form tissues. The plasma membrane helps maintain homeostasis by diffusion and osmosis. Osmosis is the diffusion of water across a membrane. Diffusion is the process by which molecules
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Diffusion through a Membrane Introduction Molecules are constantly moving. They move in straight lines unless they are deflected by other molecules or obstacles in their environment. Diffusion is the process by which the collisions between molecules cause them to continually spread apart from each other. Their movement can be described as movement from an area of greater concentration to an area of lower concentration. Diffusion continues until the molecules are equally distributed
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The Nervous System: Membrane Potential 1. Record the intracellular and extracellular concentrations of the following ions (mM/L): Intracellular Extracellular Sodium (Na+) Potassium (K+) Chloride (Cl–) 2. Excitable cells‚ like neurons‚ are more permeable to ___________ than to ___________. 3. How would the following alterations affect the membrane permeability to K+? Use arrows to indicate the change in permeability. a. An increase in the number of passive K+ channels
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anything covered in lecture may appear on the exam. Membrane Transport 1. Describe the cell permeability and membrane transport. What can enter/exit the cell on its own? What requires assistance? Why? 2. Describe membrane potential. What is it? How is it established? How does it influence the transport of charged molecules? What are the components of the electrochemical gradient? 3. What are the different types of membrane transport? Describe each in detail. Which move solutes
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Title: Ms. K Cell Membrane and Homeostasis Experiment Objective(s): The reason for this experiment is to see how starch and iodine affect each other and how a plastic bag works similar to a membrane in certain situations. Introduction: I know prior to doing this experiment that iodine mixed with starch creates a dark color and that most objects‚ organic and inorganic‚ naturally experience isotonic reactions. Hypothesis: I think that the potato will absorb more starch than the sweet potato and
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Lab report OSMOSIS TROUGH A SELECTIVELY PERMEABLE MEMBRANE Introduction: Molecules have kinetic energy. This causes the molecules of the cell to move around and bump into each other. Osmosis is a special kind of diffusion where water moves through a selectively permeable membrane (a membrane that only allows certain molecules to diffuse though). Diffusion or osmosis occurs until dynamic equilibrium has been reached. This is the point where the concentrations in both areas are equal and no
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Testing Cell Transportation Across a Membrane Introduction Cells have the amazing ability to transport certain molecules in or out of their membrane. Some require no energy to do so (passive transport) while others require energy to be processed through (active transport). There is also the transportation of water across a membrane‚ which has its own term of osmosis. Too much of something can be taken in‚ or too little enters. This especially happens to plants‚ who require water (and sun) to live
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