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Osmosis and Diffusion Passive Transport. Osmosis and Diffusion. Terms and definitions. Osmosis and Diffusion. 1.Diffusion - the process by which molecules spread from areas of high concentration, to areas of low concentration. Osmosis and Diffusion. 1.Diffusion
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Osmosis and Diffusion • Terms and definitions
Osmosis and Diffusion • 1.Diffusion - the process by which molecules spread from areas of high concentration, to areas of low concentration
Osmosis and Diffusion • 1.Diffusion • eventually spreading out evenly into the available space
Osmosis and Diffusion • Several factors can affect the rate the diffusion…… • One such factor is temperature • Higher temperatures tend to increase the rate of diffusion
Osmosis and Diffusion • 2.Solutes- a substance dissolved in fluid Ex: Salt is a solute, when it is concentrated inside or outside the cell, it will draw the water in its direction This is also why you get thirsty after eating something salty
Osmosis and Diffusion • 3.Solvent -is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute • resulting in a solution
Osmosis and Diffusion 4.Osmosis A specialized type of diffusion is the movement of a solvent (frequently water) through a semi-permeable membrane Osmosis is a type of a process where a fluid passes through a semipermeable membrane and moves from an area where a solute is present in low concentrations to an area where a solute is present in a higher concentration
Osmosis • http://www.youtube.com/watch?v=sdiJtDRJQEc Osmosis is a type of a process where a fluid passes through a semi-permeable membrane, from a higher concentration of water to a lower concentration of water
Osmosis and Diffusion • 5.Tonicity is a measure of the osmotic pressure gradient when comparing the concentration of solutes in different solutions & the following terms are used:
Hypotonic Solutions: contain a low concentration of solute (more water) When a cell is placed in a hypotonic solution, the water diffuses into the cell, causing the cell to swell Hint : po boy sandwich Osmosis and Diffusion
Osmosis and Diffusion • Hypertonic Solutions: • contain a high concentration of solute (less water) • When a cell is placed in a hypertonic solution, the water diffuses out of the cell, causing the cell to shrivel • Hint: Hyper kids
Osmosis and Diffusion • Isotonic Solutions: contain the same concentration of solute ( equal amounts of water) • When a cell is placed in an isotonic solution, the water diffuses into and out of the cell at the same rate • The fluid that surrounds the body cells is isotonic
Osmosis and Diffusion • In the real world………. • In humans, osmosis occurs in the kidneys to recover the water form waste materials of the body. The kidneys regulate the concentration of water in the blood plasma. • Kidney dialysis
Osmosis and Diffusion • In the real world In plants, osmosis occurs for example at root hairs, allowing the uptake of water from the soil.
For today • 6.1 - DEMO The effects of size and temp on diffusion • Agar that is in its gel state is porous, thus making it easier for solutions to spread. After 30 mins….. • Measuring “Halos”
For Today • 6.2 You begin here Effect of solute concentration on osmosis 10% sucrose dH20 Read materials and methods & FOLLOW DIRECTIONS 40 minutes
For Today • 6.3 Selective permeability of membranes • 6 solutions – one per bench • SHARE DATA 40 minutes AGAIN….Read materials and methods & FOLLOW DIRECTIONS
For Today • 6.4 Osmosis with red blood cells (lack cell walls) • RBC in isotonic solution • Plump round cells RBC in hypertonic solution
Hypertonic Hypotonic For Today • 6.5 Osmosis with plant cells (cell walls) Plasmolysis - cytoplasm pulls away from the cell wall due to the loss of water through osmosis
For Today • Goggles • Waste • Chemicals • Silver nitrate • Barium chloride • Gram’s iodine • Biuret • Benedict’s • Blood
PRACTICAL NEXT WEEK • Starts promptly at 8:30am • Must have note from doctor for a make-up • Review on website • Contact me before 8:30am for help • GOOD LUCK