2. CHAPTER 2 cells P. 38 - 44

3. EARLY DISCOVERIES Anton Van Leeuwenhoek - made microscopes. - saw “critters” in a drop of water. - never seen before.

4. Robert Hooke - first to see cells in slices of cork - ‘named’ cells. Led to others studying cells.

5. Matthias Schleiden - studied every part of plants. - concluded all parts were made of cells. Theodor Schwann - studied animals. - concluded that all animals were made of cells.

6. Rudolph Virchow - new cells come from other living cells. These scientists’ work led to the Cell Theory.

7. Cell theory 1. All organisms are made of cells. 2. Cells are the basic unit of structure and function in all organisms. 3. All cells come from other cells. Read p. 38 - middle p. 42.

8. STRUCTURE OF CELLS (p. 38) Scientists discovered there were parts inside the cell.

9. A) Cell Membrane Like the protective skin of the cell Like the protective skin of the cell - the outer covering. - controls what goes in and out. Food, water, oxygen enter - Wastes leave. Food, water, oxygen enter - Wastes leave. Selectively permeable: controls what enters and leaves Selectively permeable: controls what enters and leaves

10. CELL MEMBRANE

11. B) Nucleus - the ‘control center. B1) nuclear membrane -controls what goes in and out of the nucleus.

13. Contains chromosomes: - structures that hold hereditary material to determines what you look like. - made of DNA.

14. C) Cytoplasm Found inside the cell membrane outside the nucleus. Found inside the cell membrane outside the nucleus. Gel - like substance: mostly water. Gel - like substance: mostly water. Contains small structures called organelles Contains small structures called organelles -all have a “job” inside the cell.

15. CYTOPLASM

16. Cell Organelles Cells work 24 hours a day, 7 days a week Cells work 24 hours a day, 7 days a week Cell Organelle: working parts of the cell. Cell Organelle: working parts of the cell.

17. Cell Organelles 1. Mitochondria Powerhouse of cell Powerhouse of cell Food broken down and energy is released. Food broken down and energy is released. Which cells might have lots of mitochondria? Which cells might have lots of mitochondria?

19. 2. Endoplasmic Reticulum (E.R.) Folded membrane Folded membrane Like conveyer belts in the factory. Like conveyer belts in the factory. (or a highway) Transports materials throughout the cell. Transports materials throughout the cell.

21. 3. Ribosomes Most numerous organelle in the cell Most numerous organelle in the cell Some attached to E.R. Some attached to E.R. Produces protein (food) for the cell Produces protein (food) for the cell - releases energy from food. Which cells might have the most ribosomes? Which cells might have the most ribosomes?

23. 4. Lysosomes - contains chemicals (enzymes) to digest wastes and ‘worn out’ parts of the cell. - called ‘suicide sacs’ - break open and digest the cell when it dies.

25. 5. Vacuole Storage sacs Storage sacs Hold food, water, and wastes Hold food, water, and wastes Larger in plant cells Larger in plant cells

27. ASSIGNMENT: WORKSHEET “CELL STRUCTURE”. COLORED PENCILS NEEDED TOMORROW!

28. PLANT CELLS - have two different parts than animal cells. 1. Cell Wall - found outside the cell membrane. - found outside the cell membrane. - for support and protection. - non-living

29. 2. Chloroplasts - where photosynthesis takes place (turns sunlight into food). - contains chlorophyll. (green)

30. Two basic types of cells 1) Prokaryotic cells - no membranes around internal structures (no nucleus) - simplest type of cell: Bacteria ex. Pond Scum Bacteria ex. Pond Scum

31. Two basic types of cells 2) Eukaryotic cells - Nucleus surrounded a membrane. - most complex type of cell: - all plants and animals.

32. TRANSPORT IN CELLS (CH. 3 p. 74) - how materials move from cell to cell. Diffusion - the movement of particles from high concentration areas to low concentration areas. Ex. dye in water

33. Equilibrium - when the particles are spaced evenly.

34. In cells, water carries food, wastes, etc. - must enter/leave the cell through diffusion. - it must go thru the cell membrane. (it is selectively permeable)

35. Diffusion is a type of passive transport. - no energy is used to move the particles.

36. Active Transport - uses energy. - - moves particles from low concentrations to high concentrations. DRAWING ON BOARD. DRAWING ON BOARD.

37. ASSIGNMENT: SECTION REVIEW QUESTIONS. P. 45 1 P. 51 1+2 P. 78 1+2

38. Osmosis - another method of cell transport of water but it must move thru a cell membrane. - high concentration to low concentration.

39. Osmosis Examples - a wilting plant “straightens up” after being watered.

40. Reverse osmosis can kill plants - water is taken away from the roots by the drier soil. Example 2: Salt on leeches draws out their moisture.

41. ASSIGNMENT: WORKSHEET “CELL TRANSPORT”

42. CELL RESPIRATION (P. 83) - the process that creates energy from food and oxygen. - The cell gives off carbon dioxide (CO 2 ) and water (H 2 O) as wastes. - It takes place in the mitochondria.

43. Respiration gives you energy to run, breathe, talk, etc. - you take in food and oxygen. - you give off H 2 O and CO 2

44. Fermentation (P.84) - a process which creates energy without using oxygen. ex. yeast - uses nutrients and gives off CO 2 and alcohol. - used to make bread and wine/beer.

45. You only use fermentation only during heavy exercise. During exercise, you don’t get enough oxygen. - your cells release energy thru fermentation. - wastes created H2O, CO2, and lactic acid. - causes ‘burning’ feeling. - sore muscles. -releases 18x less energy than respiration.

46. ASSIGNMENT: WORKSHEET “RESPIRATION”

47. PHOTOSYNTHESIS p. 82 (light) (to make) -the process used by plants to make food. -needs light, CO 2, H 2 O, and chlorophyll - it traps energy and uses it to break down water into hydrogen and oxygen. Where does it takes place in the cell?

48. Oxygen is given off as a waste. Hydrogen combines with carbon to make a sugar (glucose).

49. Glucose is stored/used as food or used to build new structures (ex. stems) - animals eat the plants and receive energy from the stored sugars. - the energy is passed on.

50. All living things depend upon sunlight. * (except….)

51. Respiration and Photosynthesis are linked.