1. Unit 4: Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html 1

2. Discovery of Cells Robert Hooke (1600’s) discovered “little chambers” (cells) in cork plant Anton van Leeuwenhoek (1600’s)used microscope to view living things in pond water. Saw things swimming around! 2

3. Discovery of Cells, cont. Matthias Schleiden (1838) concluded plants made of cells Thoedor Schwann (1839) concluded all animals made of cells 3

4. Cell Theory 1. All living things are made up of cells. 2. Cells are the smallest working units of all living things. 3. All cells come from p_____________ cells through cell division. 4

5. Definition of Cell A cell is the smallest unit that is capable of performing life functions. 5

6. Examples of Cells Amoeba Proteus Plant Stem Red Blood Cell Nerve Cell Bacteria 6

7. Two Types of Cells Prokaryotic “pro-” means “before” (like “pre”) “karyon” means “nut” or kernel” No n______________ Older life forms are prokaryotes Eukaryotic “eu-” means “true” + “karyon”= kernel Has nucleus “newer” life forms are prokaryotic 7

8. Prokaryotic Cells Do not have o___________ surrounded by membranes V. few internal structures All prokaryotes are –one-celled organisms –B___________ http://library.thinkquest.org/C004535/prokaryotic_cells.html 8

9. Eukaryotic Cells Contain organelles surrounded by membranes Most living organisms are eukaryotic –Plants, animals, f_____, algae PlantAnimal http://library.thinkquest.org/C004535/eukaryotic_cells.html 9

10. “Typical” Animal Cell http://web.jjay.cuny.edu /~ acarpi/NSC/images/cell.gif 10

11. http://waynesword.palomar.edu/images/plant3.gif “Typical” Plant Cell 11

12. Eukaryotic Cell Parts “Organelles” 12

13. Surrounding the Cell 13

14. Cell Membrane Outer membrane of cell that controls m______ in and out of the cell Double layers of fat “phospholipid bilayer” http://library.thinkquest.org/12413/structures.html What part of this word tells you that the cell membrane is made of fats? 14

15. Cell Wall Most commonly found in –plant cells –bacteria –fungi S_____ & p_____ cells Made of carbohydrate http://library.thinkquest.org/12413/structures.html 15

16. Inside the Cell 16

17. Nucleus Directs cell activities Separated from c_______ by nuclear membrane Contains genetic material - DNA 17

18. Nuclear Membrane Surrounds nucleus Made of t____ layers Openings allow material to enter and leave nucleus http://library.thinkquest.org/12413/structures.html 18

19. Chromatin Form DNA takes most of the time. Like spaghetti Made of DNA wrapped up w/p_______. 19

20. Chromosomes In nucleus DNA wrapped up tight by proteins called “histones” Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html 20

21. Nucleolus Inside nucleus Contains RNA to build proteins http://library.thinkquest.org/12413/structures.html 21

22. Cytoplasm Gel-like mixture Surrounded by cell membrane Contains hereditary material in prokaryotes 22

23. Ribosomes Each cell contains thousands Make proteins Found on e___________ r________ & floating in the cytoplasm http://library.thinkquest.org/12413/structures.html 23

24. Endoplasmic Reticulum Moves materials around in cell Smooth type: –lacks ribosomes –Located in organisms that produce _____ like _____ Rough type (pictured): –R_____ are embedded in surface –Located in organs responsible for producing proteins, like the ________ http://library.thinkquest.org/12413/structures.html 24

25. Mitochondria Produces energy through chemical reactions by breaking down f___ & c_________. –Also known as the “powerhouse of the cell” Controls level of water and other materials in cell Recycles and decomposes proteins, fats, and carbohydrates http://library.thinkquest.org/12413/structures.html 25

26. Golgi Bodies Protein 'packaging plant' Move materials within the cell Move materials out of the cell http://library.thinkquest.org/12413/structures.html 26

27. Lysosome Digestive ‘factory' for proteins, fats, and carbohydrates Transports undigested material to c___ m_______ for removal The cell will break down if lysosome breaks! http://library.thinkquest.org/12413/structures.html 27

28. Vacuoles Membrane-bound sacs for storage, digestion, and waste removal Contains water solution Help plants maintain s______ http://library.thinkquest.org/12413/structures.html 28

29. Chloroplast Usually found in plant cells (not in animal) Contains green chlorophyll Where p__________ takes place http://library.thinkquest.org/12413/structures.html 29

30. Centrioles Used during animal cell division (not present in plant & most other cells) 30

31. Flagellum 31 Is a whiplike structure that extends outside the cell. Is used for movement.

32. Cilia Small, hairlike projections that extend outside the cell For m_______ & capturing food 32

33. Prokaryotic Cells Ribosomes DNA or RNA cytoplasm 33

34. Cell Boundaries Cell Membrane 1. Controls what goes in & out 2. Support & protection Cell Wall 1. Support & protection 34

35. Diffusion through Cell Boundaries Every cell lives in a liquid environment Membrane controls movement of dissolved molecules back & forth (in & out of cell) (Remember a solution contains a –Solvent: the substance that dissolves the other stuff (often water) –Solute: the substance that gets dissolved (salt, sugar, ions, etc.) 35

36. Concentration of Solutions The greater the ratio of solute to solvent, the higher the concentration. Ex: Solution #1: dissolve 5 g of salt in 1L of water. Concentration= 5g/L Solution #2: dissolve 10 g of salt in 1L of water. Concentration=10g/L This solution has a higher salt concentration 36

37. Diffusion In solution, particles move constantly, colliding & spreading out. Diffusion is the movement of particles from area of greater to lesser concentration (b/c of random motion.) Requires no energy to move substances across a membrane (b/c moved by random motion) 37

38. Isotonic When solute concentration is equal throughout the solution 38

39. Osmosis Video Video The diffusion of water through a membrane Some molecules are too large to move through a membrane 39

40. How Osmosis Works see Fig 7-15 on p 185 If there is a selectively permeable membrane separating 2 solutions w/differing concentrations of solute, Water will move from the side where it is in greater concentration to where it is in lesser concentration. (R to L in picture) 40

41. Concentration of Solutions Isotonic: when the concentration of particles is the same on both sides of membrane Hypertonic: “above strength”- the stronger of the 2 solutions (L side) Hypotonic: “below strength”- the less concentrated of the 2 solutions (R side) 41

42. How Osmosis Works in Cells see p 186 of text, Fig 7-16 Isotonic: Cell maintains its shape Hypertonic Hypotonic 42