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46 Cards in this Set
- Front
- Back
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What is microbiology?
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Study of organisms that are usually too small to be seen with the naked eye. Special techniques are required to isolate and grow them.
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What are the 6 groups of Microorganisms?
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1. Bacteria
2. Archaea 3. Fungi 4. Protozoa 5. Algae 6. Viruses |
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What are characteristics of Bacteria?
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Unicellular
Prokaryotic several shapes in chains or clusters cell walls of peptidoglycan reproduce with binary fission |
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What are characteristics of Archaea?
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Prokaryotic
Cell Walls lack peptidoglycan Live in extreme environments No known diseases in humans |
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Fungi
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Eukaryotic
Uni or Multi cellular No Photosynthesization Cell walls = Chitin |
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What are Protozoa?
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Unicellular
Eukaryotic Move by pseudopods, flagella or cilia variety of shapes live free or as parasites feed on organic compounds |
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What are Algae?
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Eukaryotic
Photosynthetic Uni & Multi cellular Variety of shape Cell walls = Cellulose live in water and in association with plants |
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What are Viruses?
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Very different - living/nonliving
Acellular & small Consists of only 1.DNA or RNA 2. protein coat 3.sometimes a lipid membrane reproduce using other organisms cells parasitic |
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What is the importance of Robert Hooke's discoveries?
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He saw 'cells' in cork and made a Cell Theory
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What is the importance of Robert Koch's discoveries?
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discovered proof of the existence of bacteria - with the cultivation of anthrax.
Developed Koch's postulates. |
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What is the importance of van Leeuwenhoek?
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First to see "animacules" using a simple microscope.
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What is the importance of Redi's expirements?
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He tried to disprove spontaneous generation with maggots and decaying meat
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What was the importance of Virchow's expirements?
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He discovered that living cells can arise only from living cells.
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What was the importance of Louis Pastuer's expirements in light of spontaneous generation?
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disproved spontaneous generation by using flasks with S shaped necks.
Also, his discoveries were the basis of aseptic technique. |
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What is a micrometer?
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0.000001m or 10-6m ,um
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What is a brightfield microscope?
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It uses visible light for illumination - specimens against a white background
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What is a darkfield microscope?
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a microscope that has a device to scatter light form the illuminator so that the specimen appears white against a black background. (unstained specimens)
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What is a Phase contrast microscope?
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a compound light microscope that allows examination of structures inside cells through the use of a special condenser.
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What is a differential interference contrast microscope?
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a compound light microscope, not unlike the phase contrast microscope, but using 2 light sources, produces a 3D image.
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What is a fluorescent microscope?
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a microscope that uses an ultraviolet light source - for specimens that flouresce.
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What is a scanning electron microscope?
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an electron beam is passed over the surface of the specimen.
-3D image -less resolution that the TEM |
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What is the Transmission electron microscope (TEM?
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a finely focused beam of electrons from an electron gun that pass through an ultra thin specimen.
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What are the units that are used in microbiology?
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Micrometer - 0.000001m or 10 -6m
Nanometer - 0.000000001m or 10 -9m Angstrom - 0.1nm or 10 -10m |
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How do you make a heat fixed smear?
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using the loop & aseptic technique, put a thin film of material on the slide.
Wave the slide through the flame 2-3 times. |
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What are the steps to gram staining?
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1. heat fix smear
2. primary stain (crystal violet) 3. mordant (iodine) to intensify - all bacteria purple 4. alcohol to remove stain from gram negative 5.counter stain (safranin) gram negative bacteria red 6. Results in - 2 colors of bacteria a. gram positive in purple b. gram negative in red |
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What are the shapes of:
a.) Coccus b.) Bacilli c.) Spiral |
a.) spherical
b.) rodlike c.) spiral |
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What are the varieties of Coccus?
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Diplococci- pairs
Streptococci - chains Tetrads - groups of 4 Sarcinae - cube of 8 Staphylococci- cluster or sheets |
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What are the varieties of Bacilli?
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Diplobacilli - pairs
Streptobacilli - chains coccobacili - oval shaped |
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What are the varieties of Spiral?
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Vibrios - curved rods
Spirilli - rigid corkscrews Spirochetes - flexible corkscrews |
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What is the glycocalyx of a prokaryote?
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Glycocalyx is a network of polysaccharides extending from the surface of the cell (carbohydrate gel)
-protects against phagocytosis & desiccation -aids attachment - can be a capsule or a slime layer |
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What is a flagella?
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Flagella is a thin apendage from the surface of the cel, useed for cellular locomotion.
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What are the arrangements of flagella?
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Monotrichous - single
Amphitrichous - single on each end Lophotrichous - two or more on one or both poles Peritrichous - flagella all over |
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What is the structure of flagella?
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filament - main part
hook - links to the basal body basal body - anchors to the cell wall and plasma membrane |
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What are Fimbriae?
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Fimbriae are hair like appendages used for attachment.
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What is the cell wall used for?
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composed of peptidoglycan.
1.)prevents rupturing 2.) maintains shape 3.) anchorage 4.) protects 5.) sometimes enables to cause disease 6.) site of action for antibodies |
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What is lysis?
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destructioncaused by rupture of the plasma membrane and the loss of cytoplasm
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What is a protoplast?
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Wall-less cell of a gram-positive bacteria after it has been treated with lysozyme or penicillin.
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What is a spheroplast?
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Gram-negative cell that has been treated and only has the remaining outer layer.
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What is a plasma membrane?
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selectively permeable membrane enclosing the cytoplasm of a cell.
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What is the Fluid Mosaic model?
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A way of describing the fact that the phospholipids and proteins of a plasma membrane are not stationary, but moving quite freely.
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What is Binary Fission?
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prokeryotic cell division into two daughter cells.
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What are plasmids?
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Small circular, double stranded DNA molecules.
-extrachromosomal (not crucial for survival) -replicate independently -may contain genes for: resistance, tolerance and synthesis -used in biotech |
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What is the structure of Archaea cell walls?
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May or may not have cell walls:
made of pseudomurein (similar to peptidoglycan) |
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What is the structure of Mycoplasma cell walls?
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no cell walls - plasma membrane containing sterols.
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What is the structure of the gram positive cell walls?
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Many layers of peptidoglycan, bound by teichoic acids, on top of a plasma membrane.
- may contain polysccharides or mycolic acid, periplasm. -no periplasmic space and no outer membrane |
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What is the structure of Gram Negative cell walls?
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One or maybe a few layers of peptidoglycan encased in periplasmic space and a double plasma membrane.
-No teichoic acids -contains lipopolysaccharides (LPS) and porins |
