1. Chapter 7 Cell Structure and Function
Unit 3

2. Cells
Cytology: the study of cells

3. IMPORTANT CELL STRUCTURES

4. Cell Theory
Cells are made from preexisting cells.
Cells are the smallest units of life.
All living things are made from at least one cell.

5. Cell History

6. Brief history Redi (1660’s) Hooke (1660’s) Leeuwenhoek (1670’s)
Schleiden & Schwann(1830’s)
Virchow (1850’s)
Brown (1830’s)

7. Francesco Redi 1668 Helped disprove spontaneous generation
"All life comes from life"

8. Robert Hooke
Mid-1660s
Used microscopes to diagram samples of living organisms
After looking a thin cuttings of cork, he called the chambers “CELLS” from the rooms found in monasteries

9. Anton van Leeuwenhoek Mid-1670s
Used simple microscopes to observe microscopic life in pond water
Made vast improvements to microscope construction

10. German cell biologists
1830s: Matthias Schleidan: concluded all plants made from cells
1830s: Theodor Schwann: concluded that all animals made from cells

11. Rudolph Virchow
1855
Concluded that the nucleus was responsible for cell division.

12. Robert Brown
1883
Recognized that cells contained a prominent feature and named it the
nucleus.

13. Louis Pasteur (1860s) Discovers that Cells come from Cells

14. Lynn Margulis Recognized for her work done in the 1980s proposed the Endosymbiotic Theory
“Organelles in larger, complex cells may have been free-living prokaryotic cells in the past.”
In 2000 she received the U.S. National Medal of Science

15. Cell theory (based on 200+ years of discoveries)
Cells are made from preexisting cells.
Cells are the smallest units of life.
All living things are made from at least one cell.
Cells dividing
Brief History of Cells

16. Microscopy the use of microscopes to study cells
Different types of microscopes
Light microscope
Transmission electron microscope
Scanning electron microscope

17. Cells are the basic unit of life
Unicellular: organisms made up of only one cell
Ex: bacteria, protist, fungus
Multicellular: organisms made up of more than one cell
Ex: protist, fungus, plant, animal

18. ALL CELLS CONTAIN THESE FOUR PARTS…
Plasma membrane: cell membrane, made of 2 layers of phospholipids
Cytosol: a carbohydrate and water based solution located in the cytoplasm that suspends all internal parts of the cell
Ribosomes: produces proteins
DNA: genetic material made of nucleic acids

19. Types of cells

20. There are 2 types of cells
Prokaryote: bacteria, archaebacteria
Eukaryote: protist, fungus, plant, animal

21. Prokaryotes & Eukaryotes
Bacteria pic – Life, p.459
You carry oats, I eat ‘em!
Picture1: Largest known bacterium: Thiomargarita namibiensis relative to “typical” bacteria size
Picture2: Animal cells are eukaryotic cells
?What does “kernal” represent?
?Can anyone guess what was going through the greek minds when they named these two cell types?
These words reflect the idea that prokaryotic cells evolved BEFORE nuclei developed. Eukaryotic cells have a true nucleus.
“Eu” = True
“Pro” = Before
“Karyote” from Greek karyon = Kernal

22. Prokaryote (bacteria) cell features
No membrane bound organelles (ex: nucleus, mitochondria, etc)
Small
Simple
Plasma membrane, ribosome, cytoplasm, DNA

23. Prokaryotic (Bacterial) Cell
Capsule
Label the bacteria cell in IAN on pg. 9

24. Prokaryotic cell structure
Capsule: durable outer covering that some bacteria have for protection against water, acids, and viruses
Flagella: movement
Cell wall: protective layer around plasma membrane
Pili: anchoring and DNA exchange

25. Eukaryotic Cell Complex 4 basic components + organelles
Organelles: “little organs” that carry out specialized functions within a cell
Have membrane organelles
Many variations

27. Membranes

28. Plasma (Cell) Membrane (Phospholipid Bilayer)
Outer boundary of cytoplasm
Semipermiable (only certain molecules enter & leave)
Outside
of cell
Inside
(cytoplasm)
Cell
membrane
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains

29. Phospholipid bilayer
A double layer that is an effective barrier for most molecules
Hydrophobic = “water fearing” tails in the center, prevent most things from entering
Hydrophilic = “water loving” heads attract water to edges of membrane
Outside
of cell
Inside
(cytoplasm)
Cell
membrane
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains

30. Cell membranes are mosaics of different molecules combined.

31. Proteins embedded in membranes can be:
Channels “gates” to interior for transporting into & out of cytoplasm
Receptors “windows” for gathering information about cell surroundings
Markers “name tags” that identify type of cell to others

33. Nucleus Directs cell activities
Nuclear Envelope (with pores) → outer boundary
Chromatin/Chromosomes → (DNA) carry genetic information
Nucleolus → (contain RNA) produces ribosomes
chromatin

35. Nucleus Stores ______ ______ DNA helps to regulate ______ production.
Proteins ______ cellular activity.

36. Endoplasmic reticulum
Ribosomes
small structures on endoplasmic reticulum and floating in the cytosol, that function to produce protein
Endoplasmic reticulum
an interconnecting system of “pathways,” for transport.
May be Rough ER (with ribosomes attached) or Smooth ER (without ribosomes attached).

38. Vacuole Large, sac-like compartment for storing liquids
Food, water, salt, or waste
In Animal cells they are called vesicles
Called vacuoles in plant and Protists cell

39. Golgi apparatus (body)
Modify, package, and sort protein packages for secretion, outside of cell
flattened compartments with vesicles
for secretion (packaging & shipping)

40. Lysosome
Specialized vacuole that contains digestive enzymes to destroy foreign molecules and waste

41. Understanding
A student drew this recycling symbol on their notebook cover to represent the lysosome; Why would this be an accurate representation?

42. Mitochondria
Organelle responsible for breaking down glucose molecules into ATP energy molecules
They are rod-shaped with folds, for releasing energy (ATP) by respiration

44. Understanding
Hypothesize which cells would have more mitochondria, cardiac cells or skin cells.
Why?

45. Chloroplast
Organelle in plants and algae that produces sugar molecules by photosynthesis
Why are chloroplasts green?

47. Understanding
A student takes a green plant into pitch dark room, closes the door and turns off the light. What color is the plant?

48. Cytoskeleton Hollow fibers for support & shape and to move cytoplasm
Made of
Microfilaments
Microtubules
Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Mitochondrion

49. Plant Cell Label the plant cell Plant Cell Smooth endoplasmic Vacuole
Nuclear
envelope
Ribosome
(attached)
(free)
Smooth endoplasmic
reticulum
Nucleus
Rough endoplasmic reticulum
Nucleolus
Golgi apparatus
Mitochondrion
Cell wall
Cell
Membrane
Chloroplast
Vacuole
Plant Cell

50. Animal Cell Label the animal cell Animal Cell Centrioles Nucleolus
Nucleus
Nuclear
envelope
Rough
endoplasmic
reticulum
Golgi apparatus
Smooth
Mitochondrion
Cell
Membrane
Ribosome
(free)
(attached)
Animal Cell

51. Surface to volume ratio
Because materials must be transported across cell membranes, maximizing the amount of membrane surface area increases transport efficiency.
This is why larger organisms are multicellular.

52. STOP NOTES HERE… GO ONTO THE FOLDABLES AND THE NOTES FOR TRANSPORT AND TONICS

53. Comparing surface area to volume (Complete the calculations in the margin of your notes)
Surface area: 6 mm x 6 mm x 6 sides = ___ mm2
Volume: ___ mm3
S / V = ___
Surface area: 3 mm x 3 mm x 6 sides x 8 cubes = ___ mm2
Volume = ___ mm3
S / V = ___

54. Passive or Active transport?
current
(Concentration gradient)

55. Passive vs Active transport: which requires energy output?

56. Diffusion across a membrane

57. Osmosis across a membrane

58. Osmosis
Osmosis - Diffusion of water across a selectively permeable membrane from higher water purity (high concentration) to lower water purity (low concentration)
When solutions of varying water concentrations are found across a membrane, the solutions are given names.
Hypertonic
Hypotonic
Isotonic

59. Achieving equilibrium

60. Channel vs. Carrier Proteins

61. Active transport video
Click on image to play video.

62. Types of Active Transport
Endocytosis
cell brings particles in.
Pinocytosis
Liquids are brought in.

63. Phagocytosis Phage means to “eat”
large particles (food or bacteria) are surrounded & engulfed by cell.
Examples = an ameba feeding &
a white blood cell destroying an invader.
Why are white blood cells called MacroPhages?

64. “Cell eating”

65. Exocytosis
cell deposits particles outside of cytoplasm
Secretion = cell products given off
Excretion = wastes products given off

66. Cell structure is related to it’s function
All cells are different.
Cell specialization → different cells have different jobs.
Each cell serves different needs.
Diversity on a individual scale helps stabilize the organism
Diversity on a large scale helps stabilize the ecosystem