Microbiology Midterm Study Guide questions And Answers 2024/2025

Microbiology Midterm Study Guide




Microbiology Midterm Study Guide
questions And Answers


Covers Chapters 1-13 /Week 1 (Chapters 1-3)
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1. Pasteur - Final disproof spontaneous generation
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2. Hook- Saw first microbes v v v




3. Lister -Aseptic techniques during surgery
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4. Semmelweis - Dr. had to wash hands in maternity ward v v v v v v v v v




5. Schultze & Schwann- Chemical treatment of air stops ability to produce life
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6. Koch - Developed postulates for disease microbe connection
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7. Redi - Maggot-meat experiment
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8. Leeuwenhoek - Made first microscope v v v v




Fundamental of cells: v v




Unicellular (Bacteria, Archaea, Protozoa, some fungi) and multicellular organisms (animals and plants)
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▪ All cells (prokaryotes + eukaryotes) have in common:
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Cell membrane v




DNAthat holds genetic information v v v v




Ribosomes for protein synthesis v v v v




Cytoplasm v




Eukaryotes are more complex with DNA enclosed in nucleus and membrane enclosed organelles
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Bacterial shapes:
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Cocci Rods. Vibrio Spirillum




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, Microbiology Midterm Study Guide


Spirochete Branching Filaments
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The 5 Is:
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Inoculation - Purposely moving something from 1 place to another. starts with specimen collection; lesion,
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draw blood, bird droppings, etc.
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- introducing a tiny sample into a medium to provide an env't where they multiply.
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Incubation - To hear bacteria to make it grow (usually body temp). maintaining something at the most
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favorable temperature for its development. 20 deg C & 40 deg. C02 may be required.
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- promotes multiplication of microbes over period of hours.
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- produces a culture v v




Isolation - Separate from each other
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separation of a strain from a natural, mixed population of living microbes, spreading bacteria apart as far as
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possible.
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- isolated microbes takes the form of separate colonies on solid media or turbidity (free floating cells) on
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broth.
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Inspection - Doing tests on the bug v v v v v v




appearance, cells, colony (red? shape, gram stain, sugar, etc.).
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Identification - determine type of microbe v v v v v




- specialized tests; biochemical test to determine metabolic activities specific to microbes
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- immunologic tests, genetic analysis. v v v




Microscopy Basics/Types of microscopes: v v v




1. Bright field microscope - Most widely used microscope v v v v v v v




image is darker than illuminated field
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made by putting light through specimen v v v v v




2. Dark field microscope- similar to bright field
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image is lighter than illuminated field
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bright field microscope is changed to dark field microscope by adding a condenser to the light
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3. Phase contrast microscope- used with live specimen v v v v v v




produces image with specimen against gray background
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can see internal cells
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4. Differential interreference microscope- produces colorful 3D image 2 v v v v v v v




prisms which add contrasting colors to image
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5. Fluorescence microscope – ultraviolet light for colored image against black field v v v v v v v v v v




makes an image
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6. Confocal microscope- visualizes fluorescent molecules in a single plane of focus by excluding
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out of focus light
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7. Transmission electron microscope- uses electron beams to form image v v v v v v v v




magnify images up to 100,000x
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works by transmitting electrons through specimen
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8. Scanning electron microscope – detailed 3D images of specimen v v v v v v v v




magnify up to 650,000x
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works by sending electrons to the specimen and detecting deflected electrons is characterized as a
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microscope that has lower magnifying power but can provide 3-dimensional viewing of objects.
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captures the image of the object in black and white after being stained with gold and palladium.
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9. Atomic force microscope- A microscope that uses a beam deflection system with a laser and
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photodetector to measure the beam position as a cantilever with a tip scans across the surface of a
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material. The force between the tip and sample is calculated by measuring the deflection of the
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lever and knowing the stiffness of the cantilever.
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10. Scanning tunneling microscope- uses a computer to make highly magnified image of a
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specimenv




Advantage: can view other objects as small as an individual atom, can view living organisms
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Disadvantage: expensive
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Light microscopes Vs Electron microscopes:
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1. light microscope uses light to illuminate specimens and glass lenses to magnify images.
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2. electron microscope uses a beam of electrons to illuminate specimens and magnetic lenses to
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magnify images. The resolution (the level of image detailing) is the main difference between these
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two microscopes
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Resolution:
• A scanning transmission electron microscope has achieved better than 50 pm resolution in
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annular dark-field imaging mode and magnifications of up to about 10,000,000×
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• light microscopes are limited by diffraction to about 200 nm resolution and useful magnifications
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below 2000×.
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Magnification:
• Magnification is the ability to make small objects seem larger, such as making v v v v v v v v v v v v




a microscopic organism visible. Resolution is the ability to distinguish two objects from each other.
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Light microscopy has limits to both its resolution and its magnification.
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Macromolecules key to microbiology: v v v




Macromolecules: Large organic molecules in cells. Includes nucleic acids, proteins, polysaccharides and
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lipids
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polysaccharide - is one type of macromolecule made up of monosaccharides like glucose and fructose
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