Diffusion & Osmosis Review

Use this presentation to complete Lesson 2.4

Article 1 Notes: Diffusion ●Matter (particles) move randomly

●Diffusion is the movement of particles from high concentration to low concentration

●The greater the difference in concentration, the faster the diffusion

● The higher the temperature, the faster the diffusion (particles move faster)

Article 1 Animation●http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html

Article 2 Notes: Membranes

A membrane is a barrier between two regions; in a cell it controls the flow of materials in and out●Impermeable means perfect barrier; no materials can pass through

Article 2 Notes, cont. ●Permeable means all materials can pass through

Article 2 Notes, cont.●Semi or selectively permeable means only certain materials can pass through ●it’s permeable to certain materials and impermeable to others

Article 3 Notes: Osmosis● Osmosis is a special type of diffusion that involves the movement of water from high concentration to low concentration across a semi-permeable membrane

Water Solute

Article 3 Animation: ●http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

Article 4 Notes: Osmosis & Cells●Solutions that surround cells are named for their concentration of solutes relative to the cell a. In an isotonic solution, water moves into and out of the cell at the same rate; cell maintains shape

Article 4 notes, cont: a.In a hypotonic solution, water enters a cell by

osmosisb.Animal cells, like these red blood cells, may continue

to swell until they burstc.Plant cells also swell, but cell wall prevents bursting

Article 4 notes, cont. a.In a hypertonic solution, water leaves a cell by osmosisb.Animal cells, like these red blood cells, shrivelc.In plant cells, the cell membrane shrinks away from the

cell wall

Review QuestionsThe slides that follow go over questions 18-25. Make sure you try them ON YOUR OWN before viewing the answers. Then, use the slides that follow to check your work!

NOTE: If you are completing the make up assignment, you can use the slides to test your knowledge.

Review Questions18. What is the process of moving a material from high concentration to low concentration?

a) Osmosis c) Semi-permeable membraneb) Isotonic Solution d) Diffusion

Review Questions18. What is the process of moving a material from high concentration to low concentration?

d) Diffusion

19. What is the diffusion of water molecules across a semi-permeable membrane? a) Isotonic Solution c) Impermeable Membraneb) Cytoplasm d) Osmosis

19. What is the diffusion of water molecules across a semi-permeable membrane? d) Osmosis

20. What is a barrier that separates a cell from the external environment? a) Cytoplasm c) Solutionb) Cell Membrane d) Impermeable Membrane

20. What is a barrier that separates a cell from the external environment?

b) Cell Membrane

21. The level of the solution on the left side of the membrane will …a) remain the same c) riseb) drop d) drop then rise

21. The level of the solution on the left side of the membrane will … c) rise

22. The membrane is to water molecules.a) permeable c) impermeable b) diffusion d) osmosis

22. The membrane is to water molecules.a) permeable

23. The membrane is to large molecules.a) permeable c) impermeable b) diffusion d) osmosis

23. The membrane is to large molecules. c) impermeable

24. This is a membrane.a) permeable c) impermeableb) diffusion d) semi-permeable

24. This is a membrane. d) semi-permeable

25. The ability of a living organism to maintain a steady state of internal conditions is…a) ecology c) evolution e) continuityb) homeostasis d) growth and development

25. The ability of a living organism to maintain a steady state of internal conditions is… b) homeostasis