1. Chapter 7 Cellular Structure and Function

2. Chapter 7.3 Cell Structures and Organelles

3. PROTEINS The Cell is a Factory for Making PROTEINS!!

4. Cell Organelles Cell PartFunction CytoplasmSemifluid material that surrounds the organelles and provides a place for chemical reactions to take place. CytoskeletonA network of long, thin protein fibers that form a framework and support system for the cell; anchors all the organelles NucleusControl center of the cell; contains the cell’s DNA; surrounded by nuclear membrane (envelope) RibosomesProduces proteins NucleolusProduces ribosomes Endoplasmic reticulumFolded membrane system that is the site for protein and lipid production Smooth ERArea with no ribosomes attached; place where many carbohydrates and lipids are produced Rough ERRibosomes are attached and produce proteins

5. Cell Organelles Cell PartFunction Golgi ApparatusFlattened membranes that modified, sorts, and packages proteins VacuolesTemporary storage for the cell; used to store food, enzymes, and other materials needed for the cell LysosomesStructure containing enzymes used to digest waste CentriolesUsed in cell reproduction MitochondriaProduce energy by breaking down sugars ChloroplastsCapture light energy and convert it to chemical energy (food); found in plant cells Cell wallThick, rigid fibers that surround the plasma membrane and protects the cell Cilia and FlagellaUsed for cell movement in some eukaryotic cells

7. Cytoplasm and Cytoskeleton CytoplasmSemifluid material that surrounds the organelles and provides a place for chemical reactions to take place. CytoskeletonA network of long, thin protein fibers that form a framework and support system for the cell; anchors all the organelles

8. Nucleus and Nucleolus NucleusControl center of the cell; contains the cell’s DNA; surrounded by nuclear membrane (envelope) NucleolusProduces ribosomes

9. Ribosomes Produces proteins

10. Smooth and Rough Endoplasmic Reticulum Endoplasmic reticulumFolded membrane system that is the site for protein and lipid production Smooth ERArea with no ribosomes attached; place where many carbohydrates and lipids are produced Rough ERRibosomes are attached and produce proteins

11. Golgi Apparatus Flattened membranes that modified, sorts, and packages proteins

12. Vacuole Animal Cell Plant Cell VacuolesTemporary storage for the cell; used to store food, enzymes, and other materials needed for the cell

13. Lysosomes Structure containing enzymes used to digest waste

14. Centrioles Used in cell reproduction

15. Mitochondria Produce energy by breaking down sugars

16. Chloroplasts Capture light energy and convert it to chemical energy (food); found in plant cells

17. Cell Wall Cell wallThick, rigid fibers that surround the plasma membrane and protects the cell

18. Cilia and Flagella Used for cell movement in some eukaryotic cells

19. p. 199

20. Chapter 7.4 Cellular Transport

21. Predict Food coloring demonstration – Drops of red and blue food coloring are added to opposite ends of a container of water. Hypothesize: – What will happen when the food colorings are added? – What will happen after 5 minutes?

23. Observation & Explanation Observe: – What happened to our food colorings? Explain: – How can this result be explained? Figure 7.20 © Glencoe-McGraw Hill (2007)

24. Diffusion Substances dissolved in water (solutes) move constantly in random motion; this is call Brownian Motion Causes diffusion – net movement of particles from an area where there are many particles of the substance (high concentration) to an area where there are few particles of the substance (low concentration)

25. There are two components of solution: – Solvent – a substance in which another substance is dissolved – Solute – the substance that is dissolved

26. Diffusion Movement of substances from high concentration to low concentration Caused by the RANDOM movement of particles Requires no energy input!

28. http://www.indiana.edu/~phys215/lecture/lecnotes/lecgraphics/diffusion.gif

29. http://www.indiana.edu/~phys215/lecture/lecnotes/lecgraphics/diffusion2.gif

30. Interactive Diffusion Activity: http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP1903

31. Dynamic Equilibrium Once a uniform purple color is reached, the food coloring particles continue to move randomly. However, at some point, all particles of a substance (in this case food coloring) will be as spread out as they can and there will no longer be areas of high and low concentration. When this occurs, dynamic equilibrium has been reached.

32. Diffusion in Cells

33. Three main factors affect the rate (speed) of diffusion: – Concentration of the diffusing particles – Temperature – Pressure If any of these three increases, the diffusion rate will increase. Why? Factors that Affect Diffusion

34. Facilitated Diffusion A.Water can pass easily through the plasma membrane – most substances cannot B.In facilitated diffusion, special transport proteins move ions and small molecules across the plasma membrane

35. Transport Processes Passive transport – movement of a substance across the plasma membrane without the use of the cell’s energy. Active transport – requires the use of the cell’s energy to move substances into or out of a cell across the cell membrane. Requires Energy No Energy Required

36. Cellular Transport Videos http://www.youtube.com/watch?v=dPKvHrD1eS4

37. Osmosis is the DIFFUSION OF WATER

38. Osmosis The diffusion of water across a selectively permeable membrane. – Cells must regulate this in order to maintain homeostasis. – One of three situations exists. Figure 7.22 © Glencoe-McGraw Hill (2007)

39. http://www.stolaf.edu/people/giannini/flasha nimat/transport/osmosis.swf http://www.stolaf.edu/people/giannini/flasha nimat/transport/osmosis.swf http://www.youtube.com/watch?v=sdiJtDRJQ Ec http://www.youtube.com/watch?v=sdiJtDRJQ Ec

40. Isotonic Solution Cell is in a solution that has the same concentration of water and solutes  Iso – Greek meaning “equal”  cell is in dynamic equilibrium with environment  Water enters and leaves the cell at the same rate. Figure 7.23 © Glencoe-McGraw Hill (2007)

41. Hypotonic Solution Cell is in a solution that has a lower concentration of solute than the cell  hypo – Greek meaning “under”  Net movement of water is into the cell  Causes osmotic pressure  In animals – cell could burst  In plants, cell wall prevents bursting; cell becomes firmer Figure 7.24 © Glencoe-McGraw Hill (2007)

42. Hypertonic Solution Cell is in a solution that has a higher concentration of solute than the cell.  hyper – Greek meaning “above”  Net movement of water is out of the cell  Results:  In animals – cells shrivel  In plants, central vacuole pulls away from cell wall; plant wilts Figure 7.25 © Glencoe-McGraw Hill (2007)

44. Red Blood Cells – A Comparison Is your blood pure water? What would happen to your red blood cells if pure water were to be injected into your blood stream?

45. Osmosis Examples ExampleSolution Pickles are made by immersing cucumbers in a concentrated saltwater solution. Spraying plants with a solution that contains too high a concentration of fertilizer might cause them to dry out and die. Patients undergoing surgery are given 0.9% saline (saltwater) solution. One of the oldest methods of preserving food is to pack them in saline solutions, which kill the bacteria that cause foods to spoil. Organisms that live in seawater have specialized mechanisms that prevent them from becoming dehydrated. Florists store fresh flowers in cold water to help the flowers keep their original appearance.

46. Active Transport Carrier Proteins – example: Na + / K + ATPase Pump