1. Introduction to Cells and the Microscope

2. Brief history of cells… 1665 Hooke sees “cells” in cork 1674 Van Leeuwenhoek observes living cells in water 1838 Schleiden theorizes all plants are made up of cells

3. Early Microscopes

5. 1839 Schwann theorizes all animals are made up of cells 1855 Virchow theorizes all cells are “born” from other cells Cell theory completed… STOP HERE

6. The Cell Theory 1. All living things are composed of cells. 2. Cells are basic units of structure & function in living things 3. Cells come from preexisting cells.

7. The Microscope = produces enlarged image with detail Magnification = increase in object's size Led to the discovery of cells Resolution = power to show clear detail

8. Compound Light Microscope - light passes through specimen; magnifies up to ~400 times Advantages: inexpensive; specimens alive or dead Disadvantages: not powerful; poor resolution

10. Transmission Scanning

11. Cell Diversity Cells vary in: 1.Size 2.Shape 3.Internal organization

12. 1. Size – surface area-to- volume ratio keeps cells small As cells grow, volume increases faster than surface area If cell continued to grow, it would burst

13. 2. Shape – reflects function of cell Ex: nerve cells, red blood cells

14. 3. Internal Organization Organelle = cell component that performs a specific function for the cell

15. Types of Cells: “Pro”= before; “kary”= nucleus a. DNA, ribosomes, cytoplasm & cell membrane 1.Prokaryote – simple cells (no nucleus or membrane- bound organelles) b. unicellular (bacteria)

16. 2.Eukaryote – complex cells “Eu”= true; “kary”= nucleus a. has nucleus & membrane bound organelles c. Two types of eukaryotes: 1) Animal 2) Plant b. unicellular or multicellular

17. Eukaryotic Cell Structures Organelle = cell component that performs a specific function for the cell

18. 2. Cytoplasm – space within cell a. gel-like fluid that suspends organelles a.STRUCTURE: Bilayer (2 layers) of PHOSPHOLIPIDS 1. Cell (plasma) Membrane = thin layer surrounding cell

19. Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains

20. 3. Nucleus – controls all activities of cell Three major parts: a. Nuclear membrane/ envelope = allows certain materials into & out of nucleus through pores

21. c. DNA (chromatin) – hereditary info. b. Nucleolus = makes ribosomes

23. 4. Mitochondria – makes ENERGY (ATP) for cell b. Inner, folded membrane = CRISTAE a. Has its own DNA

25. 5. Ribosomes – makes PROTEINS (directed by nucleus) a. free floating in cytoplasm b. attached to endoplasmic reticulum

26. 6. Endoplasmic Reticulum (ER) – TRANSPORT materials from ribosomes to Golgi complex a. Rough ER = ribosomes attached; transports PROTEINS

28. b. Smooth ER = no ribosomes; makes & transports LIPIDS

30. 7. Golgi apparatus (bodies) – MODIFIES, PACKAGES & SECRETES PROTEINS to inside & outside of cell a. packages proteins into VESICLES [small bubbles]

32. 8. Lysosomes –BREAK DOWN wastes, food & old cell parts using enzymes

33. 9. Cilia – short hair-like projections for MOVEMENT 10. Flagella – long, whip- like structure for MOVEMENT

35. 11. Vacuoles – fluid-filled pouch that STORES water, food & some wastes a. very LARGE in PLANT Cells; small in animal cells

36. 12. Cell wall – rigid structure outside cell membrane for STRUCTURE, SUPPORT & PROTECTION a. made of CELLULOSE b. Only in PLANT cells

37. 13. Chloroplast – converts LIGHT energy to CHEMICAL energy (photosynthesis) a. contain CHLOROPHYLL [pigment that captures light] b. Only in PLANT cells

39. 14. Centrioles –make spindle fibers in cell division a. only in ANIMAL cells

40. 15. Cytoskeleton – protein filaments that helps a cell MAINTAIN ITS’ SHAPE. a.Acts as the skeleton for a cell. b. Made from microfilaments and microtubules.

41. Cytoskeleton

42. Organelle Poster ** Get in to groups of 2 or 3 ** Pick an organelle ** Grab a poster and supplies ** YOU CAN ONLY USE 5 WORDS ON YOUR POSTER!!! ** Describe your organelle on your poster with SKETCHES or SYMBOLS

43. Poster Presentation You will get about 5 mins to rehearse what you will say in your 2 min presentation EVERY student MUST participate to get full credit! Questions to answer for the presentation: What is my organelle? What is the function of my organelle? How do my sketches describe the function of my organelle? How can I describe the function of my organelle in a way that the class will remember it for the quiz? Does my organelle work with other organelles in the cell?

44. Quiz Tomorrow!!! Ask yourself this… Can I label the structures and functions of a compound microscope? Will I be able to describe the early history of cells and microscopes from the notes? Do I understand the Cell Theory? Can I describe the function of ALL the organelles we discussed in class? IF YES…THEN YOU WILL DO GREAT!