Chapter 7: Cell Structure and Function

1. Chapter 7: Cell Structure and Function

2. Microscopes

3. History • 1400’s: magnifying glass • 1590: Jansen Bro • Used 1st compound microscope (2 lenses) • 1670-80’s: Anton van Leeuwenhoek • Used a simple light microscope (1 lens) • 1st person to observe living microorganisms • Father of Microbiology

4. Terms: • Magnification: enlarges an object’s image • Resolution: increases visible detail • Separation of 2 points

5. Light Microscopes • uses light • Simple (1 lens) • Compound (2 or more lenses) • 1 ocular eyepiece • 1 objective eyepiece • Stereomicroscope • Gives a 3-D image • Fluorescent dyes combine with video camera to produce 3-D image of cell processes (ex: cell movement)

6. Total Magnification • ocular lens x objective lens • Examples: 100 = (10x) x (10x) 430 = (10x) x (43x) • Highest magnification with a light microscope is 1500x

7. Electron Microscopes • uses beams of electrons • Transmission electron microscope (TEM) • Transmits electrons through a specimen up to 200,000x • Can study structures within a cell

8. Scanning electron microscope (SEM) • Sends electrons across the surface of a specimen to make a 3-D image up to 100,000x

9. Scanning tunneling microscope (STM) • Uses a metal probe to show the arrangement of atoms (1,000,000x) • Investigates atoms on the surface of a molecule

10. Advantages/Disadvantages of each microscope: • Light Microscope: • Advantages: can look at living specimens • Disadvantages: limited in magnification and resolution • Electron Microscope: • Advantages: greater magnification and resolution • Disadvantages: cannot view living things

11. Microscope Venn Diagram Electron Microscope Light Microscope

12. Cells

13. Robert Hooke • Studied cork (dead plant cells from the bark of a tree) • First identified cells (basic building blocks of all living things)

14. Matthias Schleiden and Theodor Schwann • Schleiden plants are made up of cells • Schwannanimals are made up of cells

15. Cell Theory • 3 parts to the cell theory- applies to all living organisms • all organisms are composed of 1 or more cells • the cell is the basic unit of structure and function (organization) of all living things • all cells come from pre-existing cells

16. Cells • Basic units of all living things • Surrounded by a plasma membrane • Have DNA (contains genetic information) • Have cytoplasm (outside the nucleus) • Contain organelles • membrane-bound structures • small, specialized structures • each has a specific function that helps cells survive • 2 groups of cells

17. Prokaryotes • Smaller in size • Do not have membrane-bound organelles • Have genetic material (DNA) but not surrounded by a membrane • Circular DNA floats in cytoplasm • Unicellular organisms (bacteria) • ****No nucleus or nuclear membrane*** • have ribosomes, cytoplasm, and cell membrane

18. Eukaryotes • Contain membrane-bound organelles • Multicellular organisms and some unicellular (amoeba, algae, and yeast) • Contain a nucleus • Control center of the cell • Contains a cell’s genetic material • Responsible for cell division • Manages all cellular functions • Identified by Rudolf Virchow • Protists, fungi, plants, and animals • Bigger in size than prokaryotes

19. Cell Types Venn Diagram Eukaryotes Prokaryotes

20. Bell Ringer: • Cell Theory: • All __________ are composed of cells. • Cells are the basic units of _______ and ________ in all organisms. • New cells are produced from ____________. 2. The cells of eukaryotes have a _________; the cells of __________ do not. 3. Eukaryotic cells also have a variety of specialized structure called ______________.

21. Levels of Organization • Cells in multicellular organisms are specialized (cell specialization) • Perform specific functions (separate roles) • Ex: nerve cells  transmit impulses • Ex: red blood cells  carry nutrients and gas throughout body • Ex: pancreatic cell  produce insulin • Ex: muscle cells  contract and relax to move parts of the body

22. organism organ systems organization organs • Cells: basic units • Ex: red blood cells, nerve cells, pancreatic cells, skin cells • Tissues: group of cells that perform a particular function • Ex: muscle tissue, epithelial tissue • Organs: group of tissues that work together • Ex: heart, liver, stomach, brain, lungs • Organ systems: group of organs that work together to perform a specific function • Ex: digestive, respiratory, nervous tissues cells

23. Organelle DNA • Chloroplasts and mitochondria have their own DNA • Lynn Margulis • Came up with the endosymbiotic theory • Suggested that mitochondria and chloroplasts came from prokaryotic cells • Formed a relationship with early eukaryotic cells

24. Cell Wall Function: • Provides additional support and protection • Allows H2O, O2, AND CO2 to pass Type of Cell: • Plant cells, fungal cells, and bacterial cells

25. Nickname: “support center” Cell Wall Unique Characteristics: • Rigid structure • Inflexible • Made of cellulose (in plants)

26. Plasma Membrane Function: • Allows substances to enter and leave a cell • Provides protection and support Type of Cell: • Plant and animal cells

27. Plasma Membrane Unique Characteristics: • Flexible boundary • Nickname: “the bouncer”

28. Nucleus Function: • Controls cell processes • Stores DNA and info to make proteins Type of Cell: • Plant and animal cells

29. Nucleus Unique Characteristics: • Has chromatin • Strands of DNA • Has nuclear envelope • Nickname: “Control Center” or “The Boss”

30. Vacuole Function: • Temporary storage of food, enzymes, wastes, and other materials Type of Cell: • Plant and animal cells

31. Vacuole Unique Characteristics: • Sac surrounded by a membrane • Bigger in plants • Nickname: “Storage closet”

32. Mitochondria Function: • Transforms energy into usable compounds by breaking down food • Cellular respiration Type of Cell: • Plant and animal cells

33. Mitochondria Unique Characteristics: • Has double membrane • Folded inner membrane  increases surface area • Occurs in varying #’s • Example: more in muscle cells • Nickname: “Powerhouse” or “Mighty-chondria”

34. Chloroplast Function: • Captures light energy and makes food • Photosynthesis Type of Cell: • Plant cells only

35. Chloroplast Unique Characteristics: • Double membrane • Plastids used for storage • Contain chlorophyll • Green pigment • Nickname: “Green sugar shack”

36. Ribosomes Function: • Where proteins are made Type of Cell: • Plant and animal cells

37. Ribosomes Unique Characteristics: • Not bound by a membrane • Can be found in cytoplasm or ER • Nickname” “Protein factory”

38. Nucleolus Function: • Makes ribosomes Type of Cell: • Plant and animal cells

39. Nucleolus Unique Characteristics: • Within the nucleus • Small and dense • Nickname: “Ribosome factory”

40. Cytoplasm Function: • Clear gelatinous fluid inside a cell • Holds organelles in place Type of Cell: • Plant and animal cells

41. Cytoplasm Unique Characteristics: • Mostly made of water • Nickname: “Celly jelly”

42. Endoplasmic Reticulum Function: • Site for cellular respiration • Rough: protein synthesis • Smooth: make and store lipids Type of Cell: • Plant and animal cells

43. Endoplasmic Reticulum Unique Characteristics: • Highly folded membranes • Internal membrane system • Nickname: “Transport system”

44. Lysosomes Function: • Digests excess or worn out organelles, food, and bacteria Type of Cell: • Animal cells

45. Lysosomes Unique Characteristics: • Contains digestive enzymes • Nickname: “Suicide sac”

46. Cytoskeleton Function: • Support structure within cytoplasm • Forms framework for the cell Type of Cell: • Plant and animal cells

47. Cytoskeleton Unique Characteristics: • Composed of tiny rods and filaments • Nickname: “Body shaper”

48. Golgi Apparatus or Golgi Body Function: • Modifies, sorts, and packages proteins Type of Cell: • Plant and animal cells

49. Golgi Apparatus or Golgi Body Unique Characteristics: • Flattened system of tubular membranes • Nickname: “Gift wrap” or “UPS”

50. Cilia Function: • Aids in locomotion and feeding Type of Cell: • Animal cells