1. Prokaryotes & Eukaryotes

2. Domains of living organisms
Bacteria
Archaea
Eucarya
Single-celled, prokaryotic organisms
Complex single and multi-celled, eukaryotic organisms

4. Prokaryotes vs Eukaryotes

5. Size and Shape of Bacteria
Epulopiscium fishelsoni
Surgeonfish symbiont
(0.6 mm)
Paramecium

6. Size and Shape of Bacteria
Pleomorphic

7. Rod-Shaped Bacteria

8. Spherical Bacteria

9. Spiral-Shaped Bacteria

10. Surface to Volume Ratio
S/V ratio
Coccus < Rod
생존력 비교
건조 환경:
빈영양 환경:
Determination of presence and significance of pathogenic organisms in food, water, and air
Fate and movement

11. Plasmid

12. Appendages (세포외 부속기관) • common in bacteria
• for motility and attachment to surfaces
Flagellum (편모)
movement through an aqueous medium

13. Appendages (세포외 부속기관) 2. Fimbria - numerous short surface appendage
- aid the cell in attachment to surface
3. Pilus
- less numerous than fimbria but longer
- only found in gram negative bacteria
- involved in a mating process (conjugation)

14. Cell Envelope • protection of cells from external environment
• glycocalyx, cell wall, cell membrane
could be missing
• account for as much as 50% of the cell mass
Glycocalyx
a coating of macromolecules that surround the cell wall
(1) slime layer
(2) capsule

15. (1) slime layer
: loose informal aggregation of carbohydrates

16. (2) Capsule
: a more rigid layer of protein that is bonded to the cell wall

17. Endospore-forming, Gram-Positive bacteria
Bacillus
Aerobic or
facultative anaerobic
Clostridium
Strictly anaerobic
(no cytochrome, ETS)
fermentative
Bacillus subtilis
B. popilliae
B. Thuringiensis (BT toxin)
Clostridium botulinus
C. butyricum
C. aceticum
C. tetani

18. 2. Cell wall - determines the shape of the cell
- gives the cell structural support
- protects the cell from rupturing caused
by the intake of water by osmosis

19. Gram Positive cell wall

20. Gram negative cell wall

22. (cytoplasmic membrane)
Cell Membrane
(cytoplasmic membrane)
• thin, flexible structure ( ~ 5nm)
• general composition: lipid bilayer
- phospholipids (30 – 40%)
- proteins ( ~ 60%)

24. • controls what gets into and out of the cell
 critical barrier between the cell interior and the environment
- nonpolar small molecules (water)
: freely pass

25. others: through protein channels
• involved in energy production
(respiration & photosynthesis)

26. Cell Protoplasm • consists of metabolites and nutrients in solution
• major constituent: water
• not true nucleus or nuclear membrane
- nucleoid: a dense area of material
- DNA: known as chromosome
a single circular molecule of double-stranded DNA
unique nucleic acid sequence  tool of detection

27. Length of a cell: ~ 2 m Length of DNA: 1200 m

28. - Plasmid: smaller accessory pieces of DNA
* codes for unique characteristics
heavy metal resistance
ability to degrade a toxic organic compounds
- Ribosomes: particles responsible for protein synthesis
size: 70S unit (50S subunit + 30S subunit)
ribosomal RNA (60%) + protein (40%)
unique sequence to the bacterial cell type
 important in the identification of bacteria

29. A View of the Eukaryotic Cell

30. enclosed by double layered lipid envelope
pores: transport of substances
nucleolus - sites of rRNA synthesis
DNA organized by histones
 chromatin  chromosome

31. Chloroplasts Found in algae and green plants
Membrane enclosed structure
Contains chlorophyll
Contains other enzymes required for photosynthesis
Thylakoids; chlorophyll-containing flattened sacs
Grana; stacks of thylakoids
Have DNA (circular)
Have ribosomes
Divide by binary fission

32. Mitochondria Generates ATP
Double membrane - structure similar to plasma membrane
Inner membrane - complex folds (cristae), large surface area
Center is matrix
Reactions occur on
cristae - ATP generation
Have DNA (circular)
Have own ribosomes
Divide by binary fission

33. Ribosomes – rRNA and Protein

34. F6.38

35. The Endoplasmic Reticulum
Rough ER - studded with
ribosomes
Protein entry point
Modifications made, lipid and carbohydrates attached
Smooth ER - no ribosomes
More enzymatic diversity
Synthesize lipids, oils,
phospholipids, steroids

36. The Golgi Complex Lysosomes Single membrane many digestive enzymes
fusion with phagosome
kill bacteria
Receives proteins transported
from RER
Mail station of the cell
; post-translational modification
determines fate of protein
packaged into secretory
vesicle