2. Introduction to Cytology or Cell Biology

3. How do we observe cells? Light microscope Visible light passes through object Lens magnify image Electron microscope Scanning - surface of object Transmission - sees through objects 100,000 X to Millions magnification power

4. How do we know what happens in each part of the cell? Radioisotopes are used to "trace" different chemical reactions through a cell. Separate cellular structures with a blender Centrifuge material and analyze each layer.

7. People who were important in early cell discovery:

8. Zacharias Jannsen (1590) Helped invent the First compound microscope

9. Robert Hooke (1665) Observed dead cork - called them “cells“ Compound Microscope

10. Anton Von Leeuwenhoek (1674) - living cells in pond water; one celled organisms -- animalcules

11. Robert Brown (1831) identifies the nucleus of a cell

12. Mattias Scleiden ( 1838 ) stated that plants are made up of cells

13. Theodor Schwann (1839) stated that animals are made up of cells

14. Rudolph Virchow (1858) Studied the pathology of cells. (ability to cause disease) 1. All cells arise from preexisting cells. 2. New cells can only arise from other living cells by the process of cell division or reproduction

15. Cell Theory 1. All living things are composed of cells 2. Cells are the fundamental building block of life 3. All cells come from pre-existing cells (life begets life)

16. PROCESSES OF CELLS All life processes involve energy changes. 1. Nutrition - food is needed for energy and building materials. 2. Digestion - breaking down reactions of food into usable parts. 3. Absorption - water, food, ions and other materials 4. Biosynthesis - cells organize many organic substances for cell activity. 5. Respiration - cell energy is released when certain organic molecules are split - energy is used for cell activity.

17. 6. Excretion - waste materials passed from cell to environment 7. Secretion - synthesized molecules which are passed out of a cell and which affect the activities of other cells (vitamins, hormones) 8. Reproduction - cells divide; unicellular - more organisms, multicellular - more cells. 9. Movement - motion of all types; cellular contractions, flowing substances within the cell 10. Egestion - elimination of insoluble compounds and nondigestible particles

18. Eukaryotic cells – advanced cells Have nucleus Plasma membrane Cytoplasm - everything between plasma membrane and nucleus Organelles Fluid Cytoskeleton – threads of microtubules and microfilaments in cytoplasm

19. Animal cells have unique structures Centrioles Lysosome Flagellum 1. 2. 3. Plant cells have unique structures Large central vacuole Cell wall 1. 2. Chloroplasts 3. Animal vs Plant Cell

21. Mitochondrion Plasma Membrane Cell Wall Central Vacuole Vesicle Ribosomes Envelope DNA Nucleolus Cytoskeleton Fibres Chloroplast Pore Golgi Body Smooth ER Rough sdfER Mitochondrion

22. Centriole

23. Plasma Membrane Protein Marker Sugar Chain Lipid Bilayer Cholesterol Proteins Embedded Protein OUTSIDE OF CELL INSIDE OF CELL

24. Cell Membrane Side Profile

25. Different membranes All have similar functions & structures Plasma membrane separates inside of cell from outside of cell Other membrane define organelles to form compartments of eukaryotic cells Forms a selectively permeable layer Lets some things in or out but not all Like a window screen

26. Nucleus

27. Envelope Double membrane Pores to get messages in and out Chromatin DNA threads Protein balls called histones - wrapping Nucleolus - site of ribosome production Nucleus - Structures

28. Nucleolus – where rRNA or Ribosomes are made

30. Ribosomes

31. Consists of 2 parts, which are made in nucleus Make protein in the Cytoplasm Produce proteins from ‘recipes’ in the nucleus copied into mRNA Some (proteins) will remain in cytoplasm Some will be exported out of cell Some will attach to membranes in cell Ribosomes are found on the endoplasmic reticulum and in the cytoplasm

32. Endoplasmic Reticulum Rough ER Smooth ER

33. Rough Endoplasmic Reticulum Rough ER - attached to nucleus Ribosomes stud surface Produces Membrane proteins - stay in cell Secretory proteins - exported from cell

34. RER makin’ Proteins!

35. Smooth Endoplasmic Reticulum No ribosomes, so not protein factories More like transport system Makes steroids, lipids Liver cells have lots of smooth ER Detoxify chemicals Supply and demand Increases tolerance to drug So higher doses needed for same effect

36. Golgi apparatus – the Post Office of the Cell

37. Refines, stores and marks molecules for shipment Looks like stack of hollow pancakes Products of ER arrive & leave via transport vesicles Moving from one sac to the next Molecules get modified Labeled and / or stored Called the cell “Post office” because it marks and directs products in the cell Golgi apparatus – what it does

38. Lysosome

39. Greek for breakdown body Recylcer Sac of strong digestive enzymes Compartmentalized for safety Can release to breakdown entire cell – “suicide sack” Functions Digest food vacuoles Digest invading bacteria Digest old organelles Lysosome

41. Lysosomal diseases Genetic disorders ‘Recipe’ is messed up so protein doesn’t work If recipe for lysosome enzyme What should get broken down doesn’t Ex. Tay Sachs Lipids aren’t broken down Build up occurs Eventually causes death Usually in before age 5

42. Mitochondria

43. Site of cellular respiration Conversion of food into energy (ATP) ATP is what cells use to make things happen (drive chemical reactions) Double membrane Big bag stuffed in smaller bag Folds of inner bag called cristae Space inside inner bag called matrix Also once free living bacteria Efficiency - gasoline engines converts 25% of energy mitochondria converts 54% of energy Mitochondria

44. contains some of its own DNA (amount varies within organisms) believed to evolved from a primitive cell engulfing it and creating a symbiotic relationship DNA in mitochondria obtained only from mother of organism.

45. Chloroplast 1. chlorophyll is green chemical that releases electrons, working like a solar panel in sunlight 2. forms glucose 3. photosynthesis 6CO 2 + 6H 2 O ---> C 6 H 12 O 6 + 6O 2 Plant Organelles Chloroplasts - in plants

46. Chloroplasts

48. Structure of Chloroplast Double membrane Grana Stack of thylakoids Hollow disk Where sunlight energy is captured and converted to chemical energy Stroma Thick fluid filling chloroplast Contains some DNA Once free-living bacteria

49. Cytoskeleton

50. Actin filaments Microtubules

51. Network of fibers Give shape to cells Allow movement of cell Move organelles around Made of microtubules and microfilaments Role of the Cytoskeleton

52. Cilia

53. Flagella

55. 9+2 Arrangment in Cilia or Flagella

56. Basal Body of a Flagella or Cilia Note the triplet rings of tubulin protein 9+0 arrangement Nine sets of rings, with no set in middle Used to set up 9+2 arrangment in cilia or flagella

57. Centrioles Cell reproduction; goes to poles of cell during cell division and helps cell divide

58. Centrioles at Work in Cell Division

59. Different kinds of cells suited for a different activity. Cell Specialization Division of Labor Different cells divide their labor each has a specific function and supports each other.

60. 1. Cell 2. Tissue 3. Organ 4. Organ system 5. Organism Levels of structure

61. Tissue Level A group of cells that are alike in structure and activity in an organism muscles - Skeletal muscle cells – motion - Cardiac muscle cells – heartbeat - Bones - support - Nerve cells - coordination, perception and automatic body functions

62. Organ Level several tissues working as a unit heart Animalsbrain stomach roots Plantsstem leaf

63. Organ System many organs involved in carrying out a function digestive nervous skeletal excretory respiratory endocrine – (hormones) circulatory muscular reproductive

64. Organism complete living thing cell tissue organ organ system organism INCREASING SIZE