Osmosis & Diffusion

Science, Grade 8

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Diffusion Osmosis Passive Transport outside of cell energy inside of cell cell membrane transport protein Cell Membrane Each cell has a cell membrane which provides structure and regulates the passage of materials between the cell and its environment. The cell membrane consists of two layers composed of proteins and lipids. The cell membrane is known as a semipermeable membrane since it allows only certain substances to move into and out of the cell. Small molecules move across a cell membrane through a method called diffusion. Diffusion is a process by which a substance moves from a place of high concentration to a place of low concentration. This process continues until the concentration of the substance is the same on both sides of the membrane. Osmosis is the diffusion of water molecules across a semipermeable membrane. The movement of water into and out of cells depends on osmosis. Active Transport Some substances move across the cell membrane from a low concentration to an area of high concentration with the use of energy. The transport of materials through a cell membrane using energy is called active transport. Passive Transport The transport of materials across the cell membrane from a high concentration to a place of low concentration without the use of energy is called passive transport. high concentration of oxygen outside the cell even concentration of oxygen inside and outside the cell high concentration high concentration low concentration low concentration Active Transport normal red blood cell low water concentration outside cell high water concentration outside cell This cell has shrunk because water has moved out of it. This cell has swollen because water has moved into it. even concentration of water inside and outside of cell Osmosis & Diffusion © Copyright NewPath Learning. All Rights Reserved. 94-4705 www.newpathlearning.com Inside of Cell Before Diffusion After Diffusion transport protein carbohydrate Outside of Cell lipid bilayer
Diffusion Osmosis Key Vocabulary Terms active transport lipid bilayer cell membrane low concentration diffusion osmosis energy passive transport high concentration semipermeable membrane lipids transport protein outside of cell energy inside of cell cell membrane transport protein Cell Membrane Each cell has a ________________________________ which provides structure and regulates the passage of materials between the cell and its environment. The cell membrane consists of two layers composed of ________________ and ________________. The cell membrane is known as a _________________________ membrane since it allows only certain substances to move into and out of the cell. Small molecules move across a cell membrane through a method called __________________. __________________ is a process by which a substance moves from a place of ____________________ concentration to a place of ______________ concentration. This process continues until the concentration of the substance is the same on both sides of the membrane. ________________ is the diffusion of water molecules across a ______________________________. The movement of water into and out of cells depends on ________________. Active Transport Describe: __________________________________________ __________________________________________________ Passive Transport Describe: __________________________________________ __________________________________________________ high concentration of oxygen outside the cell even concentration of oxygen inside and outside the cell high concentration high concentration low concentration low concentration normal red blood cell low water concentration outside cell high water concentration outside cell This cell has shrunk because water has moved out of it. This cell has swollen because water has moved into it. even concentration of water inside and outside of cell Osmosis & Di ffusion © Copyright NewPath Learning. All Rights Reserved. 94-4705 www.newpathlearning.com Inside of Cell transport protein carbohydrate Outside of Cell lipid bilayer \|xiBAHBDy01763pzY