CHAPTER 2 cells

1. CHAPTER 2cells P. 38 - 44

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

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

4. 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.

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

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

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

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

9. CELL MEMBRANE

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

11. NUCLEUS

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

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

14. CYTOPLASM

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

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

17. MITOCHONDRIA

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

19. ER

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

21. RIBOSOMES

22. 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.

23. LYSOSOMES

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

25. VACUOLE

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

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

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

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

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

31. 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

32. Equilibrium - when the particles are spaced evenly.

33. 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)

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

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

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

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

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

39. 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.

40. ASSIGNMENT:WORKSHEET“CELL TRANSPORT”

41. CELL RESPIRATION(P. 83) • the process that creates energy from food and oxygen. • The cell gives off carbon dioxide (CO2) and water (H2O) as wastes. • It takes place in the mitochondria.

42. Respiration gives you energy to run, breathe, talk, etc. - you take in food and oxygen. - you give off H2O and CO2

43. Fermentation (P.84) • a process which creates energy without using oxygen. ex. yeast - uses nutrients and gives off CO2 and alcohol. - used to make bread and wine/beer.

44. 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.

45. ASSIGNMENT:WORKSHEET“RESPIRATION”

46. PHOTOSYNTHESISp. 82 (light) (to make) • the process used by plants to make food. -needs light, CO2, H2O, and chlorophyll - it traps energy and uses it to break down water into hydrogen and oxygen. Where does it takes place in the cell?

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

48. 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.

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

50. Respiration and Photosynthesis are linked.