Chapter 3

1. Chapter 3 Cell Structure and Function Introduction to Cells Video

2. 5-1 The Cell Theory • How did van leeuwenhoek, Hooke, Schleiden, Schwann, and Virchow contribute to the development of the cell theory? • What are the parts of the cell theory?

3. All Living things are made of cells! • Cell- the basic unit of structure and function in living things • First found under lenses in microscopes

4. On to England with Robert Hooke • Used one of his microscopes to look at pieces of cork, wood, and stems • Noticed thousands of tiny chambers • Why did he call them cells? http://science-of-aging.healthaliciousness.com/timelines/hooke-history-cell-discovery.php

5. Anton van Leeuwenhoek (LAY-Vuhn-hook) • Used better lenses in the microscope • Observed organisms in pond water and then made drawings

6. Was he looking at living or non-living cells? • Why was it significant?

7. The next 200 years • Scientists found they were not only in plants • 1833- Robert Brown discovered nucleus http://www.helloquizzy.com/quizzy/results?quizzyid=936650768789608524&resultid=3

8. Germany 1838- Matthias Schleiden says, “all plant were made of cells.” 1839- Theodor Schwann says, “all animals were made out of cells.” 1855- Rudolf Virchow “New cells could be produced from the division of old cells.” All of these discoveries created the Cell Theory

9. The Cell Theory • Three parts: • 1. All living things are composed of cells • 2. Cells are the basic units of structure and function in living things • All cells come from preexisting cells • Cell theory video!

10. Picture take from: http://pearsonprophoto.com/pictures-of-the-cell-theory

11. nucleus organelles cell membrane • There are two cell types: eukaryotic cells and prokaryotic cells. • Eukaryotic cells have a nucleus. • Prokaryotic cells do not have membrane- bound organelles.

12. cell membrane cytoplasm Bacterium (colored SEM; magnification 8800x) • Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells. • All cells share certain characteristics. • Cells tend to be microscopic. • All cells are enclosed by a membrane. • All cells are filled with cytoplasm.

13. 3.2 Cell Organelles • What are the functions of the three basic structures of most cells? • How do prokaryotes and eukaryotes differ? • Cell Video!

14. Organelles-a tiny structure that performs a specialized function in the cell • Each has a special job that helps maintain the cell’s life

15. Cytoskeleton: Framework • Cytoskeleton-composed of a variety of filaments and fibers that support the cell structure and drive the cell movement

16. proteins that make up the cytoskeleton: • Microfilaments and microtubules • What do these help cells do? • Can help cells move. Ex. Amoebas

17. Cytoplasm • Can divide the Eukaryotic cell into two major parts: Nucleus and cytoplasm • Cytoplasm-material inside the cell membrane-not including the nucleus • These two structures work together to create life picture from: http://www.stephsnature.com/lifescience/cytoplasm.htm

18. Picture from: http://dbscience5.wikispaces.com/Bas

19. Nucleus • Nucleus- structure that contains the cell’s genetic material (DNA) and controls the cell’s activities • It’s Greek “pro” = before “eu” = true • Prokaryotes evolved before the nucleus

20. Nucleus Picture from: http://en.wikipedia.org/wiki/Cell_nucleus • Control center of the cell. • What does the nucleus contain? • DNA • What membrane surrounds the nucleus? • Nuclear envelope • Nuclear envelope-layer of two membranes that surrounds the nucleus of a cell

21. What does the nuclear envelope do? • Allows material to move in and out of nucleus • Nucleolus-small, dense region within most nuclei in which ribosomes are made. • Ribosomes aid in the production of proteins

22. Endoplasmic Reticulum and Ribosomes • Endoplasmic Reticulum (ER)-transports materials through the inside of the cell • Two types: Smooth and Rough ER • Smooth ER-the walls and sacs look smooth. Enzymes and chemicals are stored here

23. The Rough ER is covered with ribosomes. Why is that? • It is responsible for the synthesis of proteins • The Rough ER modifies newly made proteins Picture from: http://micro.magnet.fsu.edu/cells/endoplasmicreticulum/endoplasmicreticulum.html

24. Ribosomes: Protein Factories • Ribosomes-are the structures in which proteins are made • What cells would be crowded with them?

25. Ribosomes Picture from: http://en.wikipedia.org/wiki/Ribosome

26. Golgi apparatus-proteins are moved here after the ER to be modified and then sent out of the cell • It looks like a flattened stack of pancakes Picture from:http://en.wikipedia.org/wiki/Golgi_apparatus

27. Vesicles Vesicles – small membrane-bound sacs that divide some materials from the rest of the cytoplasm and transport these materials from place to place within the cell

28. Mitochondria • Mitochondria-change the chemical energy stored in food into compounds that the cell can use

29. Picture from: http://biology.about.com/od/cellanatomy/ss/mitochondria.htm Power House of the Cell!!!!!!!!!!!!!

30. Vacuoles • Vacuoles-saclike structure that store materials such as water, salts, proteins, and carbs • Plants have large central vacuoles filled with water • Why is this important for cells?

31. Picture From: http://en.wikipedia.org/wiki/Vacuole

32. Lysosomes: Cleanup Crews • Food and particles must be digested or broken down by a structure • Lysosomes-structures that contain chemicals and enzymes necessary for digestion in the cell

33. Lysosomes also break down organelles that have outlived their usefulness • Lysosomes are made by the Golgi apparatus Picture from: http://marionkatiemaggie.blogspot.com/2010/09/lysosomes.html

34. Centrosome and Centrioles The Centrosome is a small region of cytoplasm that produces microtubules In Animal cells, it contains two small structures called centrioles. Centrioles – cylinder-shaped organelles made of short microtubules that aid in cell division

35. Centrosome and Centrioles

36. Cell Wall • Cell Wall-Strong supporting layer around the cell membrane in plants, algae, and some bacteria • Lie outside the cell membrane • Allows water, oxygen, and carbon dioxide to pass through pretty easily. • Why is that important??? • Plant cell walls are made of cellulose

37. Chloroplasts-trap the energy of sunlight and convert it into chemical energy. What organisms are chloroplasts found in?

38. 3.3 Cell Membrane • Regulates what enters and leaves the cell. Also, aids in the protection and support of the cell. • Think Walls in House

39. What process do you think takes place in the cell membrane? • Communicate with other cells • Take in food and water • And eliminate wastes • A phospholipid bilayer forms the cell membrane • This layer makes it selectively permeable (allows some but not all materials in)

40. Cell Membrane

41. Gives a flexible structure, strong barrier between the cell and its surroundings Most have proteins embedded in lipid bilayer. So many molecules that they call cell membrane mosaic Picture From: http://en.wikibooks.org/wiki/Structural_Biochemistry/Lipids/Lipid_Bilayer

42. Cell Membrane Video Some proteins form channels or pumps which help move material Carbohydrates are used for communication Picture From: http://php.med.unsw.edu.au/cellbiology/index.php?title=Cell_Membranes_and_Compartments

43. 3.4 Diffusion and Osmosis • How do diffusion and osmosis move materials into and out of cells? • How do active and passive transport differ from each other? • What are endocytosis, phagocytosis, pinocytosis, and exocytosis?

44. Diffusion Picture from: http://en.wikipedia.org/wiki/Diffusion Particles are always moving in solution Diffusion-process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated. Equilibrium- when a concentration of a solute is the same throughout the solution

45. What does this have to do with cell membrane? If a substance is higher on one side of the cell membrane, and it is able to move through the membrane. It will move from the side with a higher concentration to the side with a lower concentration.

46. Picture from: http://good50x70.org/2007/gallery/gallery02/ Because diffusion depends upon random particle movements, substances diffuse across membranes Without requiring the cell to use energy! Even at equilibrium particles still move. Almost equal numbers of particles move in each direction, causes no further change in concentration Diffusion animation

47. Osmosis Picture From: http://www.biologycorner.com/bio1/diffusion.html Some particles are too large or too charged too cross the lipid bilayer A membrane is permeable to a substance if the substance can diffuse across it. A membrane is impermeable to a substance that can’t pass through it.

48. Most membranes are selectively permeable- Some substances can pass across them, others can’t Water passes across easily Osmosis- the diffusion of water through a selectively permeable membrane Picture From: http://www.occc.edu/biologylabs/documents/cells%20membranes/Osmosis_Definition.htm

49. How Osmosis Works I will Explain this!!!

50. Isotonic-When the concentration of two solutions is the same Hypertonic- When comparing two solutions, the solution with the greater concentration of solutes Hypotonic- When comparing two solutions, the solution with the lesser concentration of solutes. Osmosis Animation!!!