Unit 7: Topic 7.4 Cellular Transport

Transcription

1 Unit 7: Topic 7.4 Cellular Transport Name: Class key Period: Page 1 of 39

2 Topic 7.4 assignments Pages/Sections Date Assigned Date Due Page 2 of 39

3 Topic: Membrane Channels Objective: Why do molecules move via membrane channels? Molecules move from high to low Diffusion movement from HIGH to LOW concentration Page 3 of 39

4 Topic: Diffusion Objective: Describe the physical process of diffusion. Diffusion Move from HIGH to LOW concentration passive transport no energy needed Page 4 of 39

5 Topic: Simple Diffusion Objective: Diagram the physical process of simple diffusion. Simple Diffusion Move from high to low Which way will fat move? Page 5 of 39

6 Topic: Facilitated Diffusion Objective: Diagram the cellular process of facilitated diffusion. Facilitated Diffusion move from HIGH to LOW through a channel Which way will sugar move? Page 6 of 39

7 Topic: Diffusion Differences Objective: Compare the types of diffusion in cells. Diffusion directly through membrane simple diffusion no energy needed help through a protein channel facilitated diffusion (with help ) no energy needed Page 7 of 39

8 Topic: Diffusion Differences Objective: Compare the types of diffusion in cells. Simple vs. facilitated diffusion Page 8 of 39

9 Name: Period: Carefully remove this sheet from your packet to hand in. Work silently and alone to complete this graded exercise. Check for Understanding 1. Compare simple diffusion to facilitated diffusion. 2. Sketch a diagram showing both simple diffusion and facilitated diffusion. Page 9 of 39

10 Page intentionally blank Page 10 of 39

11 Topic: Osmotic Diffusion Objective: Compare osmotic diffusion to other diffusion. Osmosis: Diffusion of Water The diffusion of water across a selectively permeable membrane is called osmosis. Regulating the water flow through the plasma membrane is an important factor in maintaining homeostasis within a cell. Most cells whether in multicellular or unicellular organisms, are subject to osmosis because they are surrounded by water solutions. Page 11 of 39

12 Topic: Osmotic Diffusion Objective: Describe osmotic diffusion and its importance. Water is very important, so we talk about water separately Osmosis diffusion of water from high concentration of water to lower concentration of water across a semi-permeable membrane Page 12 of 39

13 Topic: Osmotic Control Objective: Describe osmotic control and concentration gradient. What controls osmosis? Unequal distribution of particles, called a concentration gradient, is one factor that controls osmosis. Page 13 of 39

14 Topic: Osmotic Balance Objective: Describe osmotic balance and its importance. Keeping water balance Cell survival depends on balancing water uptake & water loss Page 14 of 39

15 Topic: Isotonicity Objective: Describe osmotic isotonicity and its importance. Cells in an isotonic solution ( tonicity means concentration ) isotonic solution the concentration of dissolved substances in the solution is the same as the concentration of dissolved substances inside the cell. Page 15 of 39

16 Topic: Isotonicity Objective: Describe osmotic isotonicity and its importance. Cells in an isotonic solution Water molecules move into and out of the cell at the same rate, and cells retain their normal shape. A plant cell has its normal shape and pressure in an isotonic solution. Page 16 of 39

17 Topic: Isotonicity Objective: Describe osmotic isotonicity and its importance. Keeping right amount of water in cell Balanced conditions ( isotonic ) no difference in concentration of water between cell & environment That s better I could be better Page 17 of 39

18 Topic: Isotonicity Objective: Describe osmotic isotonicity and its importance. Keeping right amount of water in cell cell in equilibrium example: blood problem: None : water flows across membrane equally, in both directions volume of cell doesn t change Page 18 of 39

19 Topic: Hypotonicity Objective: Describe osmotic hypotonicity and its function. Cells in a hypotonic solution: Hypotonic solution: dilute solution thus low low concentration In a hypotonic solution, water enters a cell by osmosis, causing the cell to swell. Page 19 of 39

20 Topic: Hypotonicity Objective: Describe osmotic hypotonicity and its function. Cells in a hypotonic solution Plant cells swell beyond their normal size as pressure increases. ( Plants prefer this it makes the leaves firm ) Page 20 of 39

21 Topic: Hypotonicity Objective: Describe osmotic hypotonicity and its function. Keeping right amount of water in cell Freshwater - hypotonic a cell in fresh water high concentration of water around cell cell gains water KABOOM! No problem here Page 21 of 39

22 Topic: Hypotonicity Objective: Describe osmotic hypotonicity and its function. Keeping right amount of water in cell example: Paramecium problem: cells gain water, swell & can burst water continually enters paramecium cell solution: contractile vacuole pumps water out of cell Contractile vacuole in Paramecium Page 22 of 39

23 Notes page: Page 23 of 39

24 Topic: Hypertonicity Objective: Describe osmotic hypertonicity and its function. Cells in a hypertonic solution ( tonicity means concentration ) Hypertonic solution concentrated solution, thus a high solute concentration In a hypertonic solution, water leaves a cell by osmosis, causing the cell to shrink Page 24 of 39

25 Topic: Hypertonicity Objective: Describe osmotic hypertonicity and its function. Cells in a hypertonic solution Plant cells lose pressure as the plasma membrane shrinks away from the cell wall in a process called plasmolysis Page 25 of 39

26 Topic: Hypertonicity Objective: Describe osmotic hypertonicity and its function. Keeping right amount of water in cell Saltwater - hypertonic a cell in salt water low concentration of water around cell - cell loses water example: shellfish problem: cell loses water in plants: plasmolysis in animals: shrinking cell solution: take up water Page 26 of 39

27 I m shrinking, I m shrinking! I will survive! Page 27 of 39

28 Notes page: Page 28 of 39

29 Name: Period: Carefully remove this sheet from your packet to hand in. Work silently and alone to complete this graded exercise. Check for Understanding 1. Why is osmotic diffusion special? 2. Describe isotonicity. 3. Describe hypotonicity. Page 29 of 39 Cont d on back

30 4. Describe hypertonicity. Page 30 of 39

31 Topic: Passive Transport Objective: Describe the process of passive transport. Passive Transport When a cell uses no energy to move parrticles across a membrane passive transport occurs Particles go down their concentration gradient. all diffusion & osmosis are passive transport. Page 31 of 39

32 Topic: Active Transport Objective: Describe the energy and process of active transport. Active Transport Active transport Movement of materials through a membrane against a concentration gradinet and requires energy from the cell. Page 32 of 39

33 Topic: Active Transport Objective: Describe the energy and process of active transport. Active transport Cells may need molecules to move against concentration hill need to pump uphill from low to high using energy protein pump requires energy ATP Page 33 of 39

34 Topic: Active Transport Objective: Describe how active transport occurs. How active transport occurs a transport protein called a carrier protein first binds with a particle of the substance to be transported. Each type of carrier protein has a shape that fits a specific molecule or ion. Page 34 of 39

35 Topic: Endocytosis Objective: Describe how very large molecules are introduced. Transport of Large Particles Endocytosis is a process by which a cell surrounds and takes in material from its environment. The material is engulfed and enclosed by a portion of the cell s plasma membrane. resulting vacuole with its contents moves to the inside of the cell Endocytosis Page 35 of 39

36 Topic: Exocytosis Objective: Describe how very large molecules are removed. Transport of Large Particles Exocytosis is the expulsion or secretion of materials from a cell. Exocytosis Page 36 of 39

37 Name: Period: Carefully remove this sheet from your packet to hand in. Work silently and alone to complete this graded exercise. Check for Understanding 1. Is osmosis passive or active transport? Explain. 2. Where does the energy for active transport come from? 3. Sketch a cell undergoing both endocytosis and exocytosis. Page 37 of 39

38 Page intentionally blank Page 38 of 39

39 Notes page: Page 39 of 39