Download - Microbiology
![Page 1: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/1.jpg)
Prokaryotes and
Eukaryotes
![Page 2: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/2.jpg)
Classification of OrganismsHaeckel (1894)Three
kingdoms
Whittaker (1959)Five
kingdoms
Woese (1977)Six kingdoms
Woese (1990)Three
domains
ProtistaMonera
Eubacteria Bacteria
Archaebacteria Archaea
Protista Protista
EukaryaPlantaeFungi Fungi
Plantae Plantae
Animalia Animalia Animalia
![Page 3: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/3.jpg)
![Page 4: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/4.jpg)
Major DifferenceCHARACTERISTICS PROKARYOTES EUKARYOTESNucleus Non-membrane
boundMembrane bound
DNA single multipleChromosome Circular LinearHistones -/+ +Organelles - +Cell wall Peptidoglycan -/ cellulose/ chitinReproduction Binary fission Asexual/ sexualRibosomes 70s 80sETS Cell membrane mitochondria
![Page 5: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/5.jpg)
Bacteria
Bacteria are prokaryotic cells, the simplest of microbial cells. They consist of cell portoplasm contained within a retaining a structure or cell envelope.
prokaryotic simple, single-celled organisms distinct cell wals containing peptidoglycan
layerNo true nucleus (only nucleoid) free-floating DNA (some w/ plasmid)
![Page 6: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/6.jpg)
MORPHOLOGY
Prokaryotes exhibit a variety of shapes
– Most common
• Coccus– Spherical
• Bacillus– Rod or cylinder
shaped
![Page 7: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/7.jpg)
MORPHOLOGY
Prokaryotes exhibit a variety of shapes
– Other shapes• Coccobacillus
– Short round rod• Vibrio
– Curved rod• Spirillum
– Spiral shaped• Spirochete
– Helical shape• Pleomorphic
– Bacteria able to vary shape
![Page 8: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/8.jpg)
MORPHOLOGY
Division along a single plane may result in pairs or chains of cells
– Pairs = diplococci• Example: Neisseria
gonorrhoeae
– Chains = streptococci
• Example: species of Streptococcus
Arrangement:
![Page 9: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/9.jpg)
MORPHOLOGY
Division along several random planes form clusters
– Example: species of Staphylococcus
Arrangement:
Division along two or three perpendicular planes form cubical packets
– Example: Sarcina genus
![Page 10: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/10.jpg)
![Page 11: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/11.jpg)
General Structure
![Page 12: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/12.jpg)
General Structure of a Prokaryotic Cell
![Page 13: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/13.jpg)
CELL APPENDAGES
![Page 14: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/14.jpg)
FLAGELLA
• Some bacteria have protein appendages– Not essential for life
• Aid in survival in certain environments
– They include• Flagella• Pili
![Page 15: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/15.jpg)
FLAGELLA
Flagella– Long protein structure– Responsible for motility
• Use propeller like movements to push bacteria
• Can rotate more than 100,00 revolutions/minute
– 82 mile/hour
– Some important in bacterial pathogenesis
• H antigen useful in distinguishing among serovras of gram negative bacteria
![Page 16: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/16.jpg)
FLAGELLAFlagella structure has three basic parts
– Filament• Extends to exterior• Made of proteins called
flagellin
– Hook• Curved sheath• Connects filament to cell
– Basal body• Anchors flagellum into
cell wall and membrane
![Page 17: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/17.jpg)
Figure 4.8b
![Page 18: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/18.jpg)
FLAGELLAR ARRANGEMENTS
1. Monotrichous – single flagellum at one end2. Lophotrichous – small bunches arising from one end
of cell3. Amphitrichous – flagella at both ends of cell4. Peritrichous – flagella dispersed over surface of cell,
slowest
![Page 19: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/19.jpg)
FLAGELLAR ARRANGEMENTS
![Page 20: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/20.jpg)
FLAGELLA
![Page 21: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/21.jpg)
Motile Cells
![Page 22: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/22.jpg)
Axial Filaments
• Endoflagella• In spirochetes• Anchored at one end
of a cell• Rotation causes cell
to move
![Page 23: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/23.jpg)
PILI
• Rigid tubular structure made of pilin protein
•Found only in Gram negative cells
•Functions – Sexual pili—joins bacterial cells for DNA
transfer (conjugation)– Common pili—adhesion
![Page 24: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/24.jpg)
FIMBRAE
•Fine hairlike bristles from the cell surface
•Function in adhesion to other cells and surfaces
![Page 25: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/25.jpg)
CELL ENVELOPE
![Page 26: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/26.jpg)
![Page 27: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/27.jpg)
GLYCOCALYX• Coating of molecules external to the cell wall,
made of sugars and/or proteins• 2 types
1. slime layer - loosely organized and attached2. capsule – highly organized, tightly attached
• Functions– attachment– inhibits killing by white blood cells– receptor
![Page 28: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/28.jpg)
BIOFILM
Dental Plaque A polysaccharide-encased
mass of bacteria coating the surface of a tooth
Streptococcus mutans uses sucrose to synthesize a biofilm
Other bacteria can then adhere to the layer
![Page 29: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/29.jpg)
(a) The appearance of colonies composed of encapsulated cells (mucoid) compared with those lacking capsules (nonmucoid).
(b) Staining reveals the microscopic appearance of a large, well- developed capsule.
![Page 30: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/30.jpg)
CELL WALL
• Bacterial cell wall – Rigid structure– Surrounds cytoplasmic membrane– Determines shape of bacteria– Holds cell together– Prevents cell from bursting– Unique chemical structure
• Distinguishes Gram positive from Gram-negative
![Page 31: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/31.jpg)
GRAM POSITIVE GRAM NEGATIVE
![Page 32: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/32.jpg)
GRAM POSITIVE WALL
•Rigidity of cell wall is due to peptidoglycan (PTG)
– Compound found only in bacteria
•Basic structure of peptidoglycan
– Alternating series of two subunits• N-acetylglucosamine (NAG)• N-acetylmuramic acid (NAM)
– Joined subunits form glycan chain• Glycan chains held together by
string of four amino acids– Tetrapeptide chain
![Page 33: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/33.jpg)
GRAM POSITIVE WALL– Relatively thick layer of peptidoglycan
• As many as 30– Regardless of thickness, peptidoglycan is permeable to
numerous substances
– Teichoic acid component of peptidoglycan; composed of glycerol and phosphate
– Lipoteucholic acid is attached to the lipids of cytoplasmic membrane
• Gives cell negative charge
![Page 34: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/34.jpg)
GRAM POSITIVE WALL
![Page 35: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/35.jpg)
GRAM POSITIVE GRAM NEGATIVE
![Page 36: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/36.jpg)
GRAM NEGATIVE WALL
– More complex than Gram+– Only contains thin layer of
peptidoglycan• Peptidoglycan sandwiched
between outer membrane and cytoplasmic membrane
• Region between outer membrane and cytoplasmic membrane is called periplasm or periplasmic space
– Gel-like area– Most secreted proteins
contained here
![Page 37: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/37.jpg)
GRAM NEGATIVE WALL
• Outer membrane Connected to the peptidoglycan layer by lipoproteins Constructed of lipid bilayer
• Much like cytoplasmic membrane but outer layer made of lipopolysaccharides and phospholipids
• Outer membrane also called the lipopolysaccharide layer or LPS layer
– LPS severs as barrier to a large number of molecules• Small molecules or ions pass through channels called
porins• Specific channel proteins are present
![Page 38: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/38.jpg)
GRAM NEGATIVE WALL
•O-specific polysaccharide chain– Directed away from membrane
• Opposite location of Lipid A– Used to identify certain species or strains
• E. coli O157:H7 refers to specific O-side chain
•Lipid A– Portion that anchors LPS molecule in lipid bilayer– Plays role in recognition of infection
• Molecule present with Gram negative infection of bloodstream--endotoxin
![Page 39: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/39.jpg)
GRAM NEGATIVE WALL
![Page 40: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/40.jpg)
![Page 41: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/41.jpg)
Gram-Positive Membrane
![Page 42: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/42.jpg)
Gram-Negative Outer Membrane
![Page 43: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/43.jpg)
CELL WALL• Peptidoglycan layer as a target
– Many antimicrobial interfere with the synthesis of peptidoglycans or alter its structural integrity
– Examples include• Penicillin• Lysozyme
• Penicillin– Binds proteins involved in cell wall synthesis
• Prevents cross-linking of glycan chains by tetrapeptides
– More effective against Gram positive bacterium• Due to increased concentration of peptidoglycans• Penicillin derivatives produced to protect against Gram negatives
![Page 44: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/44.jpg)
CELL WALL
• Lysozymes– Produced in many body fluids including tears and
saliva– Breaks bond linking NAG and NAM
• Destroys structural integrity of cell wall
– Enzyme often used in laboratory to remove peptidoglycan layer from bacteria
• Produces protoplast in G+ bacteria• Produces spheroplast in G- bacteria
![Page 45: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/45.jpg)
![Page 46: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/46.jpg)
CELL WALL
• Differences in cell wall account for• differences in staining• Characteristics:
– Gram-positive bacterium retain crystal violet-iodine complex of Gram stain
– Gram-negative bacterium lose crystal violet-iodine complex
![Page 47: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/47.jpg)
The Gram Stain
![Page 48: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/48.jpg)
CELL WALL
• Some bacterium naturally lack cell wall– Mycoplasma
• Bacterium causes mild pneumonia• Have no cell wall
–Antimicrobial directed towards cell wall ineffective
• Sterols in membrane account for strength of membrane
![Page 49: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/49.jpg)
CYTOPLASMIC MEMBRANE
• Cell (Cytoplasmic) membrane– Delicate thin fluid structure– Surrounds cytoplasm of cell– Defines boundary– Serves as a semi permeable barrier
• Barrier between cell and external environment
![Page 50: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/50.jpg)
CELL MEMBRANE
•Structure is a lipid bilayer with embedded proteins
– Bilayer consists of two opposing layers
• Layer composed of phospholipids
– Each contains a hydrophilic phosphate head and hydrophobic fatty acid tail
![Page 51: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/51.jpg)
CELL MEMBRANE
•Membrane is embedded with numerous protein
– More that 200 different proteins– Proteins function as receptors,
channels proteins, and transport proteins
– Provides mechanism to sense surroundings
– Proteins are not stationary• Constantly changing position
– Called fluid mosaic model
![Page 52: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/52.jpg)
CYTOPLASM
![Page 53: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/53.jpg)
CYTOPLASM
• Dense gelatinous solution of sugars,• amino acids, & salts
• 70-80% water
• Serves as solvent for materials• used in all cell functions
![Page 54: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/54.jpg)
STRUCTURES WITHIN CYTOPLASM
• Bacterial cells have variety of internal structures• Some structures are essential for life
– Chromosome– Ribosome
• Others are optional and can confer selective advantage– Plasmid– Storage granules– Endospores
![Page 55: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/55.jpg)
INTERNAL STRUCTURES
Chromosome– Resides in cytoplasm
• In nucleoid space– Typically single chromosome: protein and DNA– Circular double-stranded molecule– Contains all genetic information
Plasmid– Circular DNA molecule
• Generally 0.1% to 10% size of chromosome– Extrachromosomal
• Independently replicating– Encode characteristic
• Potentially enhances survival– Antimicrobial resistance– Tolerance to toxic metals
![Page 56: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/56.jpg)
INTERNAL STRUCTURE
Ribosome– Involved in protein synthesis– Composed of large and small
subunits• Units made of protein 40%
and ribosomal RNA 60%– Prokaryotic ribosomal subunits
• Large = 30S• Small = 50S
– Small than eukaryotic ribosomes
• Difference often used as target for antimicrobials
![Page 57: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/57.jpg)
INTERNAL STRUCTURES
Storage granules– Accumulation of polymers
• Synthesized from excess nutrient– Example = glycogen
» Excess glucose in cell is stored in glycogen granules
Gas vesicles– Small protein compartments
• Provides buoyancy to cell• Regulating vesicles allows
organisms to reach ideal position in environment
![Page 58: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/58.jpg)
INTERNAL STRUCTURES
Endospores– Dormant cell types
• Produced through sporulation• Theoretically remain dormant for
100 years– Resistant to damaging conditions
• Heat, desiccation, chemicals and UV light
– Vegetative cell produced through germination
• Germination occurs after exposure to heat or chemicals
• Germination not a source of reproduction
Common bacteria genus that produce endospores include Clostridium and Bacillus
![Page 59: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/59.jpg)
![Page 60: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/60.jpg)
Inclusions• Metachromatic granules
(volutin)• Polysaccharide granules• Lipid inclusions• Sulfur granules• Carboxysomes
• Gas vacuoles• Magnetosomes
• Phosphate reserves
• Energy reserves• Energy reserves• Energy reserves• Ribulose 1,5-diphosphate
carboxylase for CO2 fixation• Protein covered cylinders• Iron oxide
(destroys H2O2)
![Page 61: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/61.jpg)
Inclusions
![Page 62: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/62.jpg)
Archaea
• primitive prokaryotes• extermophiles• lacks peptidoglycan in their cell wall• ether-linked membrane lipids
![Page 63: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/63.jpg)
Phylogenetic Tree of Archaea
![Page 64: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/64.jpg)
Archaea Morphology
Basic Archaeal Shapes : At far left, Methanococcus janaschii, a coccus form with numerous flagella attached to one side. At left center, Methanosarcina barkeri, a lobed coccus form lacking flagella. At right center, Methanothermus fervidus, a short bacillus form without flagella. At far right, Methanobacterium thermoautotrophicum, an elongate bacillus form.
![Page 65: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/65.jpg)
Archaea Morphology
• Membrane lipids– ether bonds link glycerol to hydrocarbon side
chains– lacks fatty acids– side chains composed of repeating isoprene units– major lipid components: glycerol diether and
diglycerol teraether– lipid monolayer
![Page 66: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/66.jpg)
Archaea Morphology
![Page 67: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/67.jpg)
Archaea Morphology
• Cell Wall– lacks outer membrane– pseudomurein:
• N-acetylglucosamine + N –acetyltalosaminuronic acid• β-1,3 glycosidic linkage• L-amino acids
– Polysaccharide cell walls• Methanosarcina: glucose, glucuronic acid, uronic acid
galactosamine, and acetate• Halococcus: same as Methanosarcina cell wall + Sulfate
ions
![Page 68: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/68.jpg)
Archaea Morphology
• Cell Wall– S-layers: paracrystalline surface layers
• proteins or glycoprotein arranged in various symmetries
• Functions:– structural support– interface btwn cell and its environment– selective sieve– retain proteins near cell surface
![Page 69: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/69.jpg)
Archaea Morphology
• Other Cell Walls– Natronococcus: haloalkalophilic species of
Archaea• glycoprotein cell wall contains L-glutamate as a single
type of amino acid linking glucose and glucose derivatives
![Page 70: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/70.jpg)
Archaea
• Crenarchaeaota: most thermophilic archaea are found in this group. They use sulfur compounds as electron donors or as acceptors. Not all are thermophilic.
• Euryarcheota: methanogens, halophiles, thermophiles.
• Korarcheota; found in hot springs. None have been grown in pure culture.
![Page 71: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/71.jpg)
![Page 72: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/72.jpg)
The hot springs of Yellowstone National Park, USA, were among the first places Archaea were discovered. At left is Octopus Spring, and at right is Obsidian Pool. Each pool has slightly different mineral content, temperature, salinity, etc., so different pools may contain different communities of archaeans and other microbes. The biologists pictured above are immersing microscope slides in the boiling pool onto which some archaeans might be captured for study.
![Page 73: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/73.jpg)
Salt-lovers : immense bloom of a halophilic ("salt-loving") archaean species at a salt works near San Quentin, Baja California Norte, Mexico. This archaean, Halobacterium, also lives in enormous numbers in salt ponds at the south end of San Francisco Bay; interested residents of this area should take the Dumbarton Bridge for the best views.
![Page 74: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/74.jpg)
Figure 4.22a
Eukarya
![Page 75: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/75.jpg)
Flagella and Cilia
Figure 4.23a–b
![Page 76: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/76.jpg)
Figure 4.23c
• Microtubules • Tubulin• Nine pairs + two arrangements
![Page 77: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/77.jpg)
Cell Wall
• Cell wall– Plants, algae, fungi– Carbohydrates
• Cellulose, chitin, glucan, mannan• Glycocalyx
– Carbohydrates extending from animal plasma membrane
– Bonded to proteins and lipids in membrane
![Page 78: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/78.jpg)
Plasma Membrane
• Phospholipid bilayer• Peripheral proteins• Integral proteins• Transmembrane proteins• Sterols• Glycocalyx carbohydrates
![Page 79: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/79.jpg)
Plasma Membrane• Selective permeability allows passage of some
molecules• Simple diffusion• Facilitative diffusion• Osmosis• Active transport• Endocytosis
– Phagocytosis: Pseudopods extend and engulf particles.– Pinocytosis: Membrane folds inward bringing in fluid and
dissolved substances.
![Page 80: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/80.jpg)
Eukaryotic Cell• Cytoplasm membrane:Substance inside plasma
and outside nucleus• Cytosol: Fluid portion of cytoplasm• Cytoskeleton: Microfilaments, intermediate
filaments, microtubules• Cytoplasmic streaming: Movement of cytoplasm
throughout cells
![Page 81: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/81.jpg)
Organelles• Membrane-bound
– Nucleus: Contains chromosomes– ER: Transport network– Golgi complex: Membrane formation and secretion– Lysosome: Digestive enzymes– Vacuole: Brings food into cells and provides support– Mitochondrion: Cellular respiration– Chloroplast: Photosynthesis– Peroxisome: Oxidation of fatty acids; destroys H2O2
![Page 82: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/82.jpg)
Eukaryotic Cell
• Not membrane-bound– Ribosome: Protein synthesis– Centrosome: Consists of protein fibers and
centrioles– Centriole: Mitotic spindle formation
![Page 83: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/83.jpg)
Nucleus
Figure 4.24
![Page 84: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/84.jpg)
Endoplasmic Reticulum
Figure 4.25
![Page 85: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/85.jpg)
Ribosomes
• 80S– Membrane-bound Attached to ER– Free In cytoplasm
• 70S– In chloroplasts and mitochondria
![Page 86: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/86.jpg)
Golgi Complex
Figure 4.26
![Page 87: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/87.jpg)
Lysosomes and Vacuoles
Figure 4.22b
![Page 88: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/88.jpg)
Mitochondrion
Figure 4.27
![Page 89: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/89.jpg)
Chloroplast
Figure 4.28
![Page 90: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/90.jpg)
Figures 10.2, 10.3
Endosymbiotic Theory
![Page 91: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/91.jpg)
Endosymbiotic Theory
UN 4.1
![Page 92: Microbiology](https://reader037.vdocument.in/reader037/viewer/2022110306/555455bcb4c905b2428b5400/html5/thumbnails/92.jpg)
Comparison of the Three DomainsCHARACTERISTICS BACTERIA ARCHAEA EUKARYA
Cell Nucleus - - +Chromosome Single, circular Single, circular Multiple, linearHistone Proteins - + +Peptidoglycan Cell Wall + - -
Membrane lipids Ester-linked Ether-linked Ester-linkedRibosome sedimentation rate
70s 70s 80s
Ribosome susceptibility to diptheria toxin
- + +
1st amino acid in protein
Formylmethionine Methioine ,ethionine
Chlorophyll based photosynthesis
+ (cyannobacteria) - + (algae)
Growth above 80 OC + + -Growth above 100 OC - + -