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168 terms

Micro Biology HU Spring 2014: TEST 1

Micro Biology Test Preparation/Pathogen Knowledge
STUDY
PLAY
Coccus
Vibrio
Bacillus
Spirochete
Tetrad
Staphylococcus
Streptococci
Carl Richard Woese
Famous for defining the Archaea (a new domain or kingdom of life). Created the 3 Domain system based on RNA structure.
Carl Linnaeus
Swedish Biologist who developed the 5 Kingdom System of Classification.
Staphylococcus aureus
Microorganism responsible for Staph Infection.
Bacteriology
Study of Bacteria
Mycology
Study of Fungi
Phycology
Study of Algae
Archaea
Domain which includes extremophiles.
Virology
Study of Viruses
Halophiles
Microorganisms which thrive in extremely "salty" environments.
Acellular
Term which means: "Not composed of cells."
Corona Virus
Microorganism (virus) which causes MERS.
Algae
Photosynthetic Eukaryotes.
Protozoology
Study of Protozoans.
Helminths
A polyphyletic group of eukaryotic parasites (flat worms and round worms).
Arthropods
An invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages (these include fleas, ticks, and mosquitos).
Epidemiology
A study of the spread and prevalence of disease.
Etiology
A study of the cause of disease.
Black Death
(1347-1665) Plague that killed off 1/3 of Europe's population.
Miasma
a foul, poisonous vapor.
Louis Pasteur
Father of Modern Medicine
Francesco Redi
Italian scientist who first attempted to disprove the idea of Abiogensis with his meat experiment.
Edward Jenner
English doctor who vaccinated people against small pox (with the help of the milk maids).
Louis Pasteur
Proposed Germ Theory.
Louis Pasteur
Worked with Fowl Cholera. Vaccinated Chickens by injecting aged cultures.
Antony van Leeuwenhoek
Cloth merchant who discovered "animalcules."
Louis Pasteur
Proved Fermentation due to yeast; developed Pasteurization; and disproved Abiogensis.
Louis Pasteur
Saved a boy from rabies by using dried rabid rabbit spinal cords.
Robert Koch
The Father of Medical Microbiology. Proved Germ Theory through the development of pure culture techniques.
Koch's Postulates
Method of thinking used to associate an organism with a disease.
Koch's Postulates ( All 4)
1. The organism must be found in all cases of the disease.
2. The organism should be isolated in a pure culture.
3. When the pure culture of the organism is injected into a susceptible host, the identified disease should result.
4. The identical microbe should isolated from this host and isolated in a pure culture.
Robert Koch
Was able to isolate Microbacterium Tuberculosis. Studied Cholera, Plague, and African Sleeping Sickness. Identified and discovered 20 major bacterial pathogens.
Agar
Seaweed extract.
40 Angstroms = ? (millimeters)
.000000004 milimeters
milimeter (10^?)
10^-3
micrometer (10^?)
10^-6
nanometer (10^?)
10^-9
angstrom (10^?)
10^-10
Resolution
the ability to separate two items as separate and distant entities.
Light Microscope
1000x-2000x
Max Magnification for a Light Microscope
Light Microscope
Uses visible light. Sometimes called a "bright field microscope."
Resolution Limit for a Light Microscope (____um)
.2
Compound Light Microscope
Uses visible Light, has a modified condenser which directs light towards the side of the specimen, is sometimes called Dark Field Microscope, and illuminated the specimen while leaving the surrounding dark. It typically used for bacteria which cannot be stained.
Phase Contrast Microscope
Uses visible light, takes advantage in refractive indexes (optical density) of cellular structures, to see objects light waves must be "in phase." Typically used for unstained specimens.
Differential Interference Microscope
Similar to phase contrast, contains additional light source and multiple prisms, 3-D appearance and more colorful. Also referred to as a "Nomarski Scope."
Fluorescent Scope
Modified microscope with an ultraviolet light source and protective eye filters uses dye that emit visible light when bombarded with shorter UV rays (useful in diagnosing infections using clinical specimens and fluorescent labeled antibodies.
Immunofluorescence
Fluorescent-antibody techniques. Antibodies are attached to dyes, and if the antibody binds to its specific target, the target cell will show via fluorescence microscopy.
Confocal Microscope
Laser illuminated, a laser scans over the specimen with the help of some scanning mirrors and the image is put on a computer for analysis, lasers are used because of their wavelength, salt can be seen in this microscope
Electron Microscope
Microscope that forms an image by focusing beams of electrons onto a specimen.
Scanning Electron Microscope
A microscope that is especially useful for the detailed study of the surface of a specimen; electron beams scan the surface of the sample, which is usually coated with a thin film of gold, allowing electrons on the surface to be deleted and translated into an image; result is a 3D topographic image. Can magnify from 1000x-100,000x
Transmission Electron Microscope
Magnifies about 1 million times; used to view the inside of the cell; a disadvantage is that the specimen must be: dead, frozen and cut into small slices in order to view it. Can magnify from 10,000x-1,000,000x
Eukaryotes
Nucleus: Present
Membrane Bound Organelles: Present
DNA Structure: Multiple chromosomes. Histons Present
Chlorophyll: When present, in chloroplasts.
Ribosomes: In Cytoplasm and Rough ER, larger than Prokaryotes
Reproduction: Mitosis
Cell Walls: Only in Plants and Fungi.
Prokaryotes
Nucleus: No Nucleus.
Membrane Bound Organelles: None
DNA Structure: Single closed loop. No histons.
Chlorophyll: When present, dissolved in cytoplasm.
Ribosomes: In the Cytoplasm, Smaller than Eukaryotes.
Reproduction: Binary Fission
Cell Walls:Usually Chemically Complex
Thiomargarita namibiensis
Organism believed to be responsible for cycling sulfur. (Macroscopic)
Helicobacter pylori
Bacteria responsible for causing ulcers.
Pleomorphic
Taking on many shapes.
Broth culture
Type of culture best for determining bacterial morphology/
Antigen
A substance that induces a state of sensitivity or immune responsiveness (immunity).
Epitope
a localized region on the surface of an antigen that is chemically recognized by antibodies; also called antigenic determinant
Innate Immunity
Non-specific
Non-inducible
No "memory" produced
Recognition of conserved regions
Acquired Immunity
Specific
Inducible
Memory produced
Recognition of conserved and non-conserved regions.
B Cells
Cells manufactured in the bone marrow that create antibodies for isolating and destroying invading bacteria and viruses.
T Cells
Specialized white blood cells that fight disease either by activating B cells (helper____cells) or by attacking antigens directly (killer____cells)
Helper T Cell marker(s)
CD 4
Cytotoxic T Cell marker(s)
CD 8
Regulatory T Cell marker(s)
CD 25+ and CD 4
Serology
The "in vitro" study (in glass) of interactions between antibodies and anitgens.
The 3 Domains
Archaea, Bacteria, and Eukaryote
Fimbriae
Name the structure exhibited by these cells.
Freeze Etching
Using a cryogenic knife to cut into a cell, and exposing the nuclear membrane.
Cell Mediated Immunity (T Cell)
Type of acquired immunity mediated by Helper T Cells and Cytotoxic T Cells
Shadow Casting
Spraying a cell surface with a shower of heavy metals at a 45 degree angle.
Humoral Immunity (B Cell)
Type of acquired immunity mediated by B Cells.
For bacteria, this means run
Clockwise
For bacterial, this means tumble
Counter-clockwise
Chemotaxis
moving towards (positive) or away (negative) from a chemical stimulus
Phototaxis
moving towards (positive) or away (negative) from a light stimulus
Toll-like Receptors (TLRs)
Receptors on phagocytes that often bind bacterial appendages, signaling as a trigger for the immune system.
Flagellin
Protein which composes the flagellum
Endo-flagellum
Flagellum used by bacterial spirochetes, not a true appendage, offers crude motility
Pilus
filamentous projection on a bacterial cell, used not for motility but for adhering to other bacterial cell (especially for mating) or to animal cells. Composed of "pilin" protein. Similar to "fuzz on a peach"
Atrichous
Non-motile (not mobile)
Monotrichous
1 flagellum
Amphitrichous
2 Flagellum, one on each end of the organism
Lophotrichous
Multiple flagellum on one side
Peritrichous
Multiple flagellum, surrounding the bacterial cell
The 3 parts composing the Flagella structure
The filament, the hook, and the basal body (the motor)
Conjugation
Transfer of DNA from one cell to another
Tissue Tropism
The ability of microorganisms to associate with certain tissues of the body
Virulence Factor
Any microbial factor that can promote the onset of disease
Fimbriae
Functions in attachments to substrates (help things bind to rocks in some cases), important virulence factor, composed of protein similar to pilin, and is tissue specfic
Three parts of the cell envelope
1. Glycocalyx
2. Cell Wall
3. Cell Membrane
Glcocalyx
Outer most layer of cell envelope. Two distinct regions: Slime Layer and Capsule
Slime Layer
Composed of polysaccharides, function in retention of water and cell nutrients, can be easily removed in a stream/running water
Capsule
Composed of repeating ogliosaccharide subunits or proteins, functions in the prevention of phagocytosis, cause adherence and promotion of biofilm formation
Stages of Phagocytosis
1. Endocytosis
2. Phagosome
3. Phagolysosome
4. Late-endosome
5. Exocytosis
Biofilm
A community of cells surrounded by a capsule, composed of organic and inorganic constituents, form on surfaces in aquatic systems, resistant to biocides, release of organisms into bulk fluid
Stages of Biofilm formation
1. Association
2. Adhesion
3. Microcolony Formation
4. Biofilm Formation
Biofilm Resistence to Antimicrobial Agents Steps
1. Slow penetration
2. Resistant Physiology
3. Adaptation
Impacts of Biofilms
Teeth, cooling water (Nuclear reactors), food processing, ship hulls, oil recovery, drinking water, paper manufacturing, and medical implants
Cell Wall Function
Binds cations (Mg++ and Ca++), rigidity and shape of the cell, protection from osmotic lysis, active site of certain antimicrobial agents (penicillin), antigens, and virulence factors
Peptidoglycan Layer
Composed of peptides and sugars, NAM-NAG-NAM-NAG-NAM alternating chains, connected via Beta 1-->4 linkages (Lysozymes can break this linkage)
NAM
N-acetyl-muramic acid
NAG
N-acetyl-glucosamine
Cell walls of Gram Positive Bacteria
Composed of:
1. Peptidoglycan Layers
2. Teichoic Acids
Teichoic Acids
1. Wall teichoic acids
2. Lipoteichoic acids
Wall teichoic acids
Teichoic acids within the cell wall
Lipoteichoic acids
Teichoic acids within the cell membrane
Teichoic Acids
Teichoic acids, a fortification wall, are bacterial polysaccharides of glycerol phosphate or ribitol phosphate linked via phosphodiester bonds. Play an important role in cell growth and antigenicity
Gram Positive Cells
Important antigens within the gram + cells
Lysozyme
an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria
Peptidoglycan Structure:
Alternating L and D amino acids in sets of 4 (Linked only to the NAMs, not the NAGs), Pentaglycine (5 glycines) connects the linkages of NAG-NAM chains
Gram Positive Linkages present in peptidoglycan layer?
Yes. ~100% Cross-linking. In Gram + organisms, you can have ~40 layers of peptidoglycan, all with cross linking
Gram Negative Linkages present in peptidoglycan layer?
Yes. ~20% Cross-linking. In Gram - organisms, you can have ~1-3 layers, with only ~20% cross linking
Porins
Proteins that allow the passage of certain ions and small polar molecules through membranes.
Periplasmic Space
In Gram-negative cells, the space between the cell membrane and the outer membrane containing peptidoglycan and periplasm.
Lipopolysaccharide (LPS)
Provides a protective barrier; help in adhesion, B Cell and Macrophage activator. The longer the sugar residue, the more antigenic and mucoid it becomes. It is composed of 3 sections: O Antigen region, Core polysaccharide region, and the Lipid A regions. Lipid A region is endotoxic (Causes fever, shock, spontaneous abortion, and death)
Essay Question for the first exam:
In detail, give the structure of the Gram Positive and Gram Negative cell walls. (At least a paragraph for each)
Purple color =
Gram Positive
Red color =
Gram Negative
Mordant
Means the dye forms a complex with crystal violet.
Exceptions to GP and GN structure:
1. Mycobacterium and Nocardia
2. Mycoplasma
3. Archaea
4. Rickettsia and Chlamydia
Mycobacterium produce______?
Mycolic Acid
Mycobacterium and Nocardia
Both genera cause respiratory disease, contain peptidoglycan along with high concentrations of lipids - mycolic acid, resist decolorization in the presence of acid. Therefore, these bacteria are termed Acid Fast Bacilli (AFB)
Acid Fast Stain
Heat forced the dye in. AFB- = Blue color; AFB+ = Red color
MDR
Multi-drug Resistant
XDR
Extensively Drug Resistant
Mycobacterium Avium-intracellulare Complex
A type of infection particularly common in HIV patients
Mycobacterium Leprae
Bacteria which causes leprosy
Classic drugs with which to treat TB:
Isoiazid and Rifampin
Mycoplasma
Are found in humans and most have no cell wall. Can cause pneumonia. Not affected by antibiotics which target the cell wall, no morphology
Rickettsia
Obligate Intracellular parasite, cannot be grow outside of the cell (but IS NOT a virus), transmitted by arthropods, (Rocky Mountain Spotted Fever and Typhus)
Chlamydia
Obligate Intracellular parasite, Chlamydia trachomatis is the most often seen, most common venerial disease in the world, the most common cause of preventable blindness in the world today
Cell Membrane
Composition: Phosopholip bilayer with embedded protein
Function: Osmotic barrier, transport, energy extraction, nutrient catalysis and processing, enzymatic biosynthesis and degradation
Protoplasm
DNA
Bacterial Cytoskeleton
Ribosomes
Inclusions
Endospores
Nucleoid Region
DNA containing region. No membrane around the nucleoid region. Super-coiled DNA.
Plasmids
Extra chromosomal DNA elements. Can replicate independent of chromosome. Sometimes aid organisms by giving them a selective advantage (ex: antibacterial agent resistance, metal resistance, virulence factors).
Resistance Plasmids
R Plasmids
Fertility Plasmids
F Plasmids
Bacterial Cytoskeleton
Chemically similar to tubulin and actin. May help stabilize structure of bacterial cell and play a role in movement.
Ribosome
Small particles composed of rRNA and protein which direct the synthesis of proteins during translation. Composed of large and small subunits. Not bound to membrances. Smaller in prokaryotes than in eukaryotes.
Velocity Sedimentation
How fast or slow a ribosome moves through a sucrose gradient. Dependent on mass and surface area.
Granules
Storage sites for nutrients or gas. Include: Lipids, Polysaccharides, Sulfur/Iron, and Polyphosphates.
Endospores
Resilient structures which maintain the bacterial cell through periods of stress. Resistant to heat, radiation, dessication, and chemical treatment. Resistant outer coat contains high concentrations of dipicolinic acid and Ca++. Present in selected genera. [Bacillus (aerobic) and Clostridium (anaerobic)]
Vegetative Cell
Metabolically active cell
Endospore cycle
Vegetative cell --> Sporulating Cell --> Spore --> Germinating Spore --> Outgrowth --> Vegetative Cell
Endospore Formers:
Bacillus anthracis (anthrax)
Bacillus cereus (GI infection)
Clostridium botulinum (botulism - muscles can't contract)
Clostridium tetani (tetnus - muscles stay contracted)
Clostridium perfringens (gas gangrene)
Clostridium perfringens
gas gangrene, works through the production of exospores (hard to find), produces lots of CO2 and H2, blows tissues apart.
Clostridium difficile
Pseudomembranous colitis (is a big problem in hospitals)
Clostridium botulinum
Exotoxin blocks release of acetylcholine at neuromuscular junction preventing muscle contraction. Often transmitted through the food chain.
Kuru
Disease affected Fore Tribe of New Guinea. Transmitted through cannibalism. Caused loss of muscle coordination, dementia, progressive insomnia, and death. Resistant to nucleases, proteases, heat, irradiation
Nuclease
Destroys nucleic acid
Diseases similar to Kuru in animals:
Scrapie (in sheep/goats), Bovine Spongiform Encephalopathy (Mad Cow Disease), Chronic Wasting Disease (Deer/elk)
Diseases similar to Kuru in humans:
CJD, Fatal Familial Insomnia, GSS, and New Variant CJD (nvCJD)
Common features (Kuru)
Presence of amyloid rods, made of proteins, prions, associated with long incubation periods culminating in death
Prions
Infectious protein particles. Textbook definition: The protinaceous infectious agent of transmissable spongiform encephalopathies.
The difference between prions and normal tissue is _________________
secondary structure
Prions
Protein sequencing revealed them to be proteins 27,000-30,000 daltons and composed of 145aa. Very similar to a protein in normal cells. Prions were termed: PrP^sc. Normal protein termed: PrP^c Normal proteins functions in binding Cu++
Transmission of Prions:
Horizontal transfer (i.e. cannibalism)
Genetic Inheritance
Spontaneous Mutation
Effects of Prions:
Misfolding happens without the coding of nucleic acids. Misfolded proteins compel other proteins to misfold as well. Alpha helices form to Beta sheets. Rogue proteins aggregate to form amyloid fibils. Amyloid fibrils kill neurons.
Mycobacterium tuberculosis
Bacteria which causes tuberculosis.

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