1. Ch. 6 Warm-Up
What are the 2 main types of cells? Which Domains do they consist of?
List 3 ways that eukaryotes differ from prokaryotes.

2. Ch. 6 Warm-Up How is the size of a cell related to its function?
Name 5 organelles or cell structures and their function.

3. Pick up handout on back counter.
Warm-Up Activity:
Pick up handout on back counter.
Complete this handout for your warm-up activity.

4. Compare and contrast Animal vs. Plant Cells Animal Cell Plant Cell
Ch. 6 Warm-Up
Compare and contrast Animal vs. Plant Cells
Animal Cell
Plant Cell

5. Ch. 6 Warm-Up What is the structure & function of: Microtubules
Microfilaments
Intermediate filaments

6. Ch. 6 Warm-Up What is the function of: Plasmodesmata Gap junctions
Tight junctions
Desmosomes

7. Chapter 6
A Tour of the Cell

8. Three differences between prokaryotic and eukaryotic cells.
You Must Know
Three differences between prokaryotic and eukaryotic cells.
The structure and function of organelles common to plant and animal cells.
The structure and function of organelles found only in plant cells or only in animal cells.

9. How We Study Cells
Biologists use microscopes and the tools of biochemistry to study cells

10. Size range of cells
Note that light microscopes can not magnify as well as electron microscopes

11. Light Microscopy (LM) vs. Electron Microscopy (EM)

12. Comparisons of Scopes Light Electron
Visible light passes through specimen
Refracts light so specimen is magnified
Magnify up to 1000X
Specimen can be alive/moving
Color
Focuses a beam of electrons through/onto specimen
Magnify up to 1,000,000 times
Specimen non-living and in vacuum
Black and white

13. Electron Microscopy Transmission (TEM) Scanning (SEM) 2-D
11/5/2017
Electron Microscopy
Transmission (TEM)
Scanning (SEM)
2-D
Creates a flat image with extreme detail
Can enhance contrast by staining atoms with heavy metal dyes
3-D
Used for detailed study of surface of specimen
Gives great field of depth

14. Studying cell structure & function
Cell fractionation - take apart cells, separate major organelles
Ultracentrifuge - applies force 1 million times the force of gravity to separate further the cell organelles with the most dense at the bottom

15. 2 Types of Cells:
Prokaryotes: Domain Bacteria & Archaea
Eukaryotes (Domain Eukarya): Protists, Fungi, Plants, Animals

16. A Prokaryotic Cell (bacteria)

17. Prokaryote Vs. Eukaryote
“before” “kernel”
No nucleus
DNA in a nucleoid
Cytosol
No organelles other than ribosomes
Small size
Primitive
i.e. Bacteria & Archaea
“true” “kernel”
Has nucleus and nuclear envelope
Cytosol
Membrane-bound organelles with specialized structure/function
Much larger in size
More complex
i.e. plant/animal cell

18. Cell Size and Scale
Scale of the Universe:
rse_2012

19. Cells must be small to maintain a large surface area to volume ratio
Large S.A. allows  rates of chemical exchange between cell and environment

20. Surface Area Example (Animal):
Small Intestine: highly folded surface to increase absorption of nutrients
Villi: finger-like projections on SI wall
Microvilli: projections on each cell

21. Folds  Villi  Microvilli

22. Surface Area Example (Plant):
Root hairs: extensions of root epidermal cells; increase surface area for absorbing water and minerals

23. Nucleus Function: control center of cell Contains DNA
Surrounded by double membrane (nuclear envelope)
Continuous with the rough ER
Nuclear pores: control what enters/leaves nucleus
Chromatin: complex of DNA + proteins; makes up chromosomes
Nucleolus: region where ribosomal subunits are formed

24. Nucleus Contains DNA Function: control center of cell
Surrounded by double membrane (nuclear envelope)
Continuous with the rough ER
Nuclear pores: control what enters/leaves nucleus
Chromatin: complex of DNA + proteins; makes up chromosomes
Nucleolus: region where ribosomal subunits are formed

25. Ribosomes Function: protein synthesis Composed of rRNA + protein
Large subunit + small subunit
Types:
Free ribosomes: float in cytosol, produce proteins used within cell
Bound ribosomes: attached to ER, make proteins for export from cell

26. Endomembrane System:
Regulates protein traffic & performs metabolic functions

27. Endoplasmic Reticulum (ER)
Network of membranes and sacs
Types:
Rough ER: ribosomes on surface
Function: package proteins for secretion, send transport vesicles to Golgi, make replacement membrane
Smooth ER: no ribosomes on surface
Function: synthesize lipids, metabolize carbs, detox drugs & poisons, store Ca2+

28. Endoplasmic Reticulum (ER)

29. Golgi Apparatus
Function: synthesis & packaging of materials (small molecules) for transport (in vesicles); produce lysosomes
Series of flattened membrane sacs (cisternae)
Cis face: receives vesicles
Trans face: ships vesicles

30. Lysosomes
Function: intracellular digestion; recycle cell’s materials; programmed cell death (apoptosis)
Contains hydrolytic enzymes

31. Vacuoles
Function: storage of materials (food, water, minerals, pigments, poisons)
Membrane-bound vesicles
Eg. food vacuoles, contractile vacuoles
Plants: large central vacuole -- stores water, ions

35. Parts of plant & animal cell p 108-109

37. Mitochondria Function: site of cellular respiration
Double membrane: outer and inner membrane
Cristae: folds of inner membrane; contains enzymes for ATP production; increased surface area to  ATP made
Matrix: fluid-filled inner compartment

38. Chloroplasts Function: site of photosynthesis Double membrane
Thylakoid disks in stacks (grana); stroma (fluid)
Contains chlorophylls (pigments) for capturing sunlight energy

39. Illustrative Examples:
Variations within molecules provide a wider range of functions:
Chlorophylls

40. Endosymbiont theory Mitochondria & chloroplasts share similar origin
Prokaryotic cells engulfed by ancestors of eukaryotic cells
Evidence:
Double-membrane structure
Have own ribosomes & DNA
Reproduce independently within cell

41. Peroxisomes Functions: break down fatty acids; detox alcohol
Involves production of hydrogen peroxide (H2O2)

42. Cytoskeleton: network of protein fibers
Function: support, motility, regulate biochemical activities

43. 3 Types of Cytoskeleton Fibers:
Microtubules
Microfilaments
Intermediate Filaments
Protein = tubulin
Largest fibers
Shape/support cell
Track for organelle movement
Forms spindle for mitosis/meiosis
Component of cilia/flagella
Protein = actin
Smallest fibers
Support cell on smaller scale
Cell movement
Eg. ameboid movement, cytoplasmic streaming, muscle cell contraction
Intermediate size
Permanent fixtures
Maintain shape of cell
Fix position of organelles

44. 3 Types of Cytoskeleton Fibers:
Microtubules
Microfilaments
Intermediate Filaments

46. Centrosomes: region from which microtubules grow
Also called microtubule organizing center
Animal cells contain centrioles

47. Cilia & Flagella Flagella: long and few; propel through water
Cilia: short and numerous; locomotion or move fluids
Have “9+2 pattern” of microtubules

48. Extracellular Matrix (ECM)
Outside plasma membrane
Composed of glycoproteins (ex. collagen)
Function: Strengthens tissues and transmits external signals to cell

49. Intercellular Junctions (Animal cells)
Tight junctions: 2 cells are fused to form watertight seal
Desmosomes: “rivets” that fasten cells into strong sheets
Gap junctions: channels through which ions, sugar, small molecules can pass

50. Plant Cells Cell wall: protect plant, maintain shape
Composed of cellulose
Plasmodesmata: channels between cells to allow passage of molecules

51. Plant Cells Only
Animals Cells Only
Central vacuoles
Lysosomes
Chloroplasts
Centrioles
Cell wall of cellulose
Flagella, cilia
Plasmodesmata
Desmosomes, tight and gap junctions
Extracellular matrix (ECM)

52. Harvard cell video
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