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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ethanol on the permeability of beetroot cell membranes. Prediction: By exposing a membrane to a solvent‚ ethanol‚ it will increase its permeability. So the higher the concentration of the solvent‚ the more permeable the membrane will be. But if the concentration of the ethanol is beyond a certain limit‚ it may break down the cell membrane to the point where there is in fact no overall effect as the ethanol would disturb the lipids in the membrane. Therefore‚ more of the red pigment in the
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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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Title: The effect on temperature on beet cell membranes. Introduction A cell membrane or plasma membrane is very important in protecting cells. A cell membrane is a thin layer that protects the cells. The membrane is filled with lipids and proteins. The cell membrane protects the cell from ions and molecules that enter and exit the cells. I hypothesize that at -5 degrees Celsius‚ the color intensity will be a 1. I hypothesize that at 5 degrees Celsius‚ the color intensity will be a 2
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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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is to determine the stress that various alcohols have on biological membranes. Membranes within cells are composed mainly of lipids and proteins and often serve to help maintain order within a cell by containing cellular materials. Different membranes have a variety of specific functions. One type of membrane-bound vacuole found in plant cells‚ the tonoplast‚ is quite large and usually contains water. In beet plants‚ this membrane-bound vacuole also contains a watersoluble red pigment‚ betacyanin
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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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Investigating the effect of temperature on plant cell membranes The purpose of this activity is: • to practise experimental and investigative skills • to investigate the effect of temperature on cell membrane structures Procedure SAFETY: Always carry scalpels clasped to a tile and with the tip pointing away from you. Beetroot cells contain pigments called betalains that give the tissue its dark purple-red colour. The pigment is contained in the cell vacuole. Investigation
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