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Section 4: Diffusion and Osmosis
Chapter 3: Cells Section 4: Diffusion and Osmosis Chapter 3: Cells Section 4: Diffusion and Osmosis
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Body Spray Graphing Activity Passive Transport Presentation
Chapter 3: Cells Section 4: Diffusion and Osmosis Agenda Do Now! Body Spray Graphing Activity Passive Transport Presentation
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Chapter 3: Cells Section 4: Diffusion and Osmosis Do Now! Think about the graphs you have made in the past. In your Biology notebook, write down as many characteristics of a good line graph as you can think of.
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What kind of energy is represented by this motion?
Chapter 3: Cells Section 4: Diffusion and Osmosis Molecules move randomly What kind of energy is represented by this motion? In all matter, molecules are always moving randomly and bumping in to each other.
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“diffuse” means “spread out” or “to spread out”
Chapter 3: Cells Section 4: Diffusion and Osmosis Diffusion Diffusion is the movement of molecules in a fluid or gas from a region of higher concentration to a region of lower concentration “diffuse” means “spread out” or “to spread out”
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Chapter 3: Cells Section 4: Diffusion and Osmosis
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Is a type of passive transport
Chapter 3: Cells Section 4: Diffusion and Osmosis Diffusion Is a type of passive transport Passive transport uses no energy to move molecules “Passive” means “not participating readily or activ- ely”
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Chapter 3: Cells Section 4: Diffusion and Osmosis “Diffusion”
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Chapter 3: Cells Low concentration Equal concentration
Section 4: Diffusion and Osmosis Low concentration Equal concentration High concentration
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Chapter 3: Cells “Diffusion of Food Coloring in a Water Solution”
Section 4: Diffusion and Osmosis “Diffusion of Food Coloring in a Water Solution”
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Molecules move “down” a concentration gradient
Chapter 3: Cells Section 4: Diffusion and Osmosis Concentration Gradient A concentration gradient is the difference in the concentration of a substance from one region to another. Molecules move “down” a concentration gradient
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Chapter 3: Cells Section 4: Diffusion and Osmosis
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Chapter 3: Cells Section 4: Diffusion and Osmosis learn
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Osmosis Osmosis is diffusion across a semi-permeable membrane.
Chapter 3: Cells Section 4: Diffusion and Osmosis Osmosis Osmosis is diffusion across a semi-permeable membrane. Because it is a type of diffusion, osmosis is also passive transport Osmosis is critical to the health of cells
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Chapter 3: Cells Section 4: Diffusion and Osmosis "Osmosis"
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Check for Understanding: How many fingers?
Chapter 3: Cells Section 4: Diffusion and Osmosis Check for Understanding: How many fingers?
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Solutions with a Membrane
Chapter 3: Cells Section 4: Diffusion and Osmosis Solutions with a Membrane The concentration of a solute may be different on one side of a membrane than the other. The words isotonic, hypertonic, and hypotonic help us to compare these two environments. “iso” = “same” “hyper” = “more” “hypo” = “less”
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Solutions with a Membrane
Chapter 3: Cells Section 4: Diffusion and Osmosis Solutions with a Membrane An Isotonic solution has the same amount of solute on both sides of the membrane or cell. A Hypertonic solution has more solute than inside the membrane or cell. A Hypotonic solution has less solute than inside the membrane or cell.
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Chapter 3: Cells Section 4: Diffusion and Osmosis “same” “more” “less”
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Facilitated Diffusion
Chapter 3: Cells Section 4: Diffusion and Osmosis Facilitated Diffusion Facilitated diffusion is a special case of osmosis. Molecules that are too big and/or too polar need help to cross the cell membrane! Molecules that cannot normally cross the cell membrane may be helped across by transport channel proteins
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Chapter 3: Cells Section 4: Diffusion and Osmosis
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Chapter 3: Cells Section 4: Diffusion and Osmosis
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