Apidays New York 2024 - Scaling API-first by Ian Reasor and Radu Cotescu, Adobe
Bio 120 lecture 3 2011 2012
1. MICROBIAL CELL
BIOLOGY
Biology 120 Lecture 3
Reference: Chapter 3 and 4 TORTORA
Parungao-Balolong 2011
Tuesday, July 5, 2011
2. LECTURE OUTLINE
• Observation of
Microorganisms
• Size, Shape and
arrangement of Cells
• Functional Anatomy
of Prokaryotes
• Functional Anatomy
of Eukaryotes Parungao-Balolong 2011
Tuesday, July 5, 2011
3. OBSERVATION OF
MICROORGANISMS
• Units of • 1000 nm = 1
Measure µm
• 1 µm = 10–6 m • 0.001 µm = 1
= 10 –3 mm nm
• 1 nm = 10 –9 m
= 10–6 mm
Parungao-Balolong 2011
Tuesday, July 5, 2011
4. OBSERVATION OF
MICROORGANISMS
• Simple Microscope (1 • Compound Microscope
lens) ( more than 1 lens)
• Magnification differs
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Parungao-Balolong 2011
5. OBSERVATION OF
MICROORGANISMS
• RECALL: Microscopy!
• Resolution
• Refractive Index
• Immersion Oil
Parungao-Balolong 2011
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6. TYPES OF
MICROSCOPES
• Brightfield
versus Darkfield
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7. TYPES OF MICROSCOPES
• Phase Contrast
• accentuates diffraction of
light that passes through
the specimen
• Differential Interference
Contrast
• uses two beams of light
Parungao-Balolong 2011
Tuesday, July 5, 2011
8. TYPES OF MICROSCOPES
• Fluorescence
• fluorescent substance absorbs
UV light and emit visible light
• Confocal
• laser illuminates each plane in
a specimen (3D image)
• *** fluorochromes
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9. TYPES OF MICROSCOPES
• Measures sound waves
that are reflected back
from an object
• For microbial cells on
surface
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10. ELECTRON MICROSCOPY
• Transmission Electron Microscope (Res 2.5nm)
• Scanning Electron Microscope (Res 20nm)
Parungao-Balolong 2011
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11. PREPARING SPECIMENS: WET
MOUNT
• Wet Mount
• viable
• heat fixing not
done
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12. WET MOUNT
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13. STAINING SPECIMENS
•Stained
•dead
•fixation (heat or ethanol)
•Smear
• Simple
• Differential
• Special
Parungao-Balolong 2011
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14. SMEAR
PREPARATION
FROM
COLONIES OR
BROTH
CULTURE
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15. FIXATION
• Process by which the internal and external structures
of cells and microorganisms are preserved and fixed
in position
• Inactivates enzymes that might disrupt cell
morphology
• Toughens cell structures to prevent changes during
staining and observation
• Usually microbes are killed when fixed
Parungao-Balolong 2011
Tuesday, July 5, 2011
16. TYPES OF FIXATION
•Heat-fixation •Chemical fixation
• By flaming air-dried • Used to protect fine
smear gently cellular substructure;
morphology of larger,
• Adequately preserves more delicate microbes
overall morphology but
not structures within • Penetrates cells and
cells react with cellular
components (proteins
and lipids)
• Example: alcohol,
formaldehyde, acetic
Parungao-Balolong 2011
Tuesday, July 5, 2011
18. SIZE, SHAPE &
ARRANGEMENT OF CELLS
• Average Size: • Environmental
0.2um-1.0um x Factors
2-8um
• pleiomorphism
• Shape Based on:
• devoid of cell wall
• Genetics
• monomorphism
• uniqueness for
each bacteria Parungao-Balolong 2011
Tuesday, July 5, 2011
19. SIZE, SHAPE &
ARRANGEMENT OF CELLS
Parungao-Balolong 2011
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20. SIZE, SHAPE &
ARRANGEMENT OF CELLS
Parungao-Balolong 2011
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21. SIZE, SHAPE &
ARRANGEMENT OF CELLS
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22. SIZE, SHAPE &
ARRANGEMENT OF CELLS
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23. SIZE, SHAPE &
ARRANGEMENT OF CELLS
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24. SIZE, SHAPE &
ARRANGEMENT OF CELLS
Stella sp. Haloarcula sp.
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25. FUNCTIONAL ANATOMY
OF PROKARYOTES
• Basics of Prokaryotes
• One circular chromosome not enclosed in a
membrane
• no histones
• no organelles
• Cell walls with peptidoglycans
• Divides via Binary Fission Parungao-Balolong 2011
Tuesday, July 5, 2011
26. FUNCTIONAL ANATOMY
OF PROKARYOTES
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27. FUNCTIONAL ANATOMY
OF PROKARYOTES
Plasma Selectively permeable barrier, mechanical
Membrane boundary of cell, nutrient and waste
transport, location of many metabolic
processes (respiration, photosynthesis),
detection of environmental cues for
chemotaxis
Gas Vacuole Buoyancy for floating in aquatic
environments
Ribosomes Protein synthesis
Inclusion Bodies Storage of carbon, phosphate and other
substances
Parungao-Balolong 2011
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29. PLASMA MEMBRANE
Membrane is as
viscous as olive
oil.
Proteins move to
function.
Phospholipids
rotate
and move laterally.
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30. PLASMA MEMBRANE
Selective permeability allows passage of some molecules
Enzymes for ATP production
Photosynthetic pigments on foldings called chromatophores or
thylakoids; chlorosomes; photosynthetic lamellae
green sulfur bacteria
purple sulfur bacteria
purple non-sulfur bacteria Parungao-Balolong 2011
Tuesday, July 5, 2011
31. PLASMA MEMBRANE
Damage to the membrane by alcohols,
quaternary ammonium (detergents),
and polymyxin antibiotics causes
leakage of cell contents.
Parungao-Balolong 2011
Tuesday, July 5, 2011
32. PLASMA MEMBRANE
EUBACTERIA
Ester linkage
Weaker linkage
ARCHAEBACTERIA
Ether linkage
Stronger linkage
NOTE: POINT OF LINKAGE = POINT
OF BREAKDOWN
Parungao-Balolong 2011
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33. MEMBRANE
TRANSPORT: RECALL
Simple diffusion:
Movement of a solute
from an area of high
concentration to an
area of low
concentration.
Facilitative diffusion:
Solute combines with
a transporter protein
in the membrane.
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34. MEMBRANE
TRANSPORT: RECALL
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35. MEMBRANE
TRANSPORT: OSMOSIS
Osmosis: The movement of water
Osmotic pressure: The pressure needed to stop
the movement of water across the membrane.
Parungao-Balolong 2011
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36. MEMBRANE
TRANSPORT: RECALL
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37. INCLUSION BODIES
Metachromatic granules Phosphate reserves
(volutin)
Corynebacterium diptheria
Polysaccharide granules Energy reserves
Example: Glycogen
Lipid inclusions (PHBs) Energy reserves
Mycobacterium, Bacillus, Azotobacter
Sulfur granules Energy reserves
Corynebacterium diptheria
Carboxysomes
Ribulose 1,5-diphosphate carboxylase for CO2 fixation
Nitrifying Bacteria
Gas vacuoles/Gas vesicles Protein covered cylinders
Magnetosomes Iron oxide
(destroys H2O2)
Aquaspirillum magnetotacticum
Parungao-Balolong 2011
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39. RIBOSOMES
16S ribosomal DNA =
prokaryotes
18S ribosomal DNA =
eukaryotes Parungao-Balolong 2011
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40. FUNCTIONAL ANATOMY
OF PROKARYOTES
Nucleoid Localization of Genetic Material
(DNA)
Periplasmic Contains hydrolytic enzymes and
Space binding proteins for nutrient
processing and uptake
Cell Wall Gives bacteria shape and
protection from lysis in dilute
solutions
Parungao-Balolong 2011
Tuesday, July 5, 2011
41. PERIPLASMIC SPACE/
PERIPLASM
• Space between the
plasma membrane
and the outer
membrane
• 40% in G- minimal
in G+
• Loose PG (murein)
and some proteins
• For Gram +
counterpart are
exoenzymes
Parungao-Balolong 2011
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42. CELL WALL
Prevents osmotic lysis
Made of peptidoglycan (in bacteria)
Parungao-Balolong 2011
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43. PEPTIDOGLYCAN (PG)
Polymer of disaccharide
N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)
Linked by polypeptides
Parungao-Balolong 2011
Tuesday, July 5, 2011
46. PEPTIDOGLYCAN (PG)
Thin peptidoglycan
No teichoic acids
Outer membrane
Parungao-Balolong 2011
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47. TEICHOIC ACIDS : G+
Lipoteichoic acid links
to plasma membrane
Wall teichoic acid links
to peptidoglycan
May regulate
movement of cations
Polysaccharides
provide antigenic
variation
Parungao-Balolong 2011
Tuesday, July 5, 2011
48. OUTER MEMBRANE : G-
Lipopolysaccharides, lipoproteins, phospholipids
Forms the periplasm between the outer membrane and the plasma
membrane.
Protection from phagocytes, complement, and antibiotics
O polysaccharide antigen, e.g., E. coli O157:H7
Lipid A is an endotoxin
Porins (proteins) form channels through membrane.
Parungao-Balolong 2011
Tuesday, July 5, 2011
49. CELL WALLS & GRAM STAIN
Crystal violet-iodine crystals form in cell.
Gram-positive
Alcohol dehydrates peptidoglycan
CV-I crystals do not leave
Gram-negative
Alcohol dissolves outer membrane and leaves
holes in peptidoglycan.
CV-I washes out
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51. GRAM + VS GRAM -
Parungao-Balolong 2011
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52. GRAM + VS GRAM -
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53. WHEN GRAM STAIN NOT APPLICABLE
Mycoplasmas
Lack cell walls
Sterols in plasma
membrane
Archaea
Wall-less or
Walls of
pseudomurein (lack
NAM and D amino
Parungao-Balolong 2011
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54. TARGETING THE CELL WALL
Lysozyme digests disaccharide in peptidoglycan.
Penicillin inhibits peptide bridges in peptidoglycan.
Protoplast (complete) is a wall-less cell.
Spheroplast (partial) is a wall-less Gram-positive
cell.
L forms (reversible) are wall-less cells that swell
into irregular shapes.
Protoplasts and spheroplasts are susceptible to
osmotic lysis.
Parungao-Balolong 2011
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55. PROTOPLASTS
Parungao-Balolong 2011
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56. FUNCTIONAL ANATOMY
OF PROKARYOTES
Capsules and Slime Layers Resistance to phagocytosis,
adherence to surfaces
Fimbriae and Pili Attachment to surfaces,
bacterial mating
Flagella Movement
Endospore Survival under harsh
environmental conditions
Parungao-Balolong 2011
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57. FIMBRIAE & PILI
Fimbriae allow
attachment
Pili are used to
transfer DNA from
one cell to another
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58. FIMBRIAE & PILI
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59. THE F PLASMID
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60. ENDOSPORE
Resting cells
Resistant to desiccation,
heat, chemicals
Bacillus, Clostridium
Sporulation: Endospore
formation
Germination: Return to
vegetative state
Parungao-Balolong 2011
Tuesday, July 5, 2011
63. ENDOSPORE RESISTANCE
15% of spore dry weight consists of dipicolinic acid complexed
with calcium ions
DPA directly involved in spore heat resistance
GENERA:
• Clostridium
• Bacillus
• Sporolactobacillus
• Sporosarcina
Parungao-Balolong 2011
Tuesday, July 5, 2011
64. OUTSIDE THE WALL:
GLYCOCALYX
Outside cell wall
Usually sticky
A capsule is neatly organized
A slime layer is unorganized and
loose
Extracellular polysaccharide allows
cell to attach
Capsules prevent phagocytosis
Parungao-Balolong 2011
Tuesday, July 5, 2011
65. OUTSIDE THE WALL:
GLYCOCALYX
Capsule Staining
Parungao-Balolong 2011
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66. OUTSIDE THE CELL
WALL : FLAGELLA
Outside cell wall
Made of chains of
flagellin
Attached to a protein
hook
Anchored to the wall
and membrane by the
basal body
Parungao-Balolong 2011
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67. OUTSIDE THE CELL
WALL : FLAGELLA
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68. OUTSIDE THE CELL
WALL : FLAGELLA
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69. MOTILITY
Rotate flagella to run or tumble
Move toward or away from stimuli (taxis)
Flagella proteins are H antigens
(e.g., E. coli O157:H7)
Parungao-Balolong 2011
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70. MOTILITY
Parungao-Balolong 2011
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71. MOTILITY
Parungao-Balolong 2011
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72. CYTOPLASM
Cytoplasm is the substance inside the
plasma membrane.
Nuclear area (nucleoid)
Parungao-Balolong 2011
Tuesday, July 5, 2011
73. FUNCTIONAL ANATOMY
OF EUKARYOTES
• Observation of
Microorganisms
• Size, Shape and
arrangement of Cells
• Functional Anatomy
of Prokaryotes
• Functional Anatomy
of Eukaryotes Parungao-Balolong 2011
Tuesday, July 5, 2011