Microscopy Parts and Functions Quiz

Microscopy

• Compound Microscope Parts & Functions: (Detailed diagrams recommended for full understanding)
  • Eyepiece/ocular: Magnifies the image.
  • Objective lenses: Magnify the image, varying magnification for different lenses.
  • Stage: Supports the specimen.
  • Condenser: Focuses light on the specimen.
  • Diaphragm: Controls light intensity.
  • Coarse adjustment knob: Moves stage for initial focusing.
  • Fine adjustment knob: Precisely focuses the image.
  • Arm: Supports the microscope body.
  • Base: Provides support.
• Resolving Power: Ability to distinguish between two closely spaced points.
• Working Distance: Distance between the objective lens and the specimen.
• Total Magnification: Product of eyepiece and objective lens magnification.
• Parfocalization: A microscope that maintains focus when changing magnification.

Microscopy Resolution

• Resolution is the ability to distinguish between two closely spaced points.

Microbial Characteristics

• Protozoa: Eukaryotic, animal-like, single-celled organisms.
• Algae: Eukaryotic, photosynthetic, single-celled or multicellular (often aquatic).
• Cyanobacteria: Prokaryotic, photosynthetic, single-celled or filamentous organisms (blue-green algae).

Aseptic Technique

• Vital for preventing contamination during microbiological procedures.

Bacterial Characteristics

• Prokaryotic: Lack a nucleus and membrane-bound organelles.
• Bacterial Morphology (Fig. 8.1): Consider shapes (cocci, bacilli, spirilla) and arrangements (chains, clusters).

Fungal Characteristics

• Eukaryotic: Possess a nucleus and other membrane-bound organelles.
• Yeast: Unicellular, oval or spherical.
• Mold: Multicellular, filamentous (hyphae). Differences: growth form, structure.

Mycology, Myceteae, Dimorphic

• Mycology: The study of fungi.
• Myceteae: Fungi, (fungal family group)
• Dimorphic: Fungi exhibiting two distinct morphological forms in different conditions.

Smear Preparation

• Liquid Media: Prepare smear by taking a loopful of liquid culture, placing it on the slide, and air-drying.
• Solid Media: Use a sterile loop to lightly emulsify a small amount of solid media, placing it on the slide, and air-drying.

Heat-Fixing

• Purpose: Kills the cells and adheres them to the slide.

Staining

• Simple Staining: Uses a single dye to visualize cell morphology.
• Differential Staining: Uses multiple dyes to distinguish between cell types (e.g., Gram stain, acid-fast stain).

Basic and Acidic Dyes

• Basic Dyes: Positively charged dyes that bind to negatively charged cell components (like cell membranes).
• Acidic Dyes: Negatively charged dyes that bind to parts with positive charges.

Capsule

• Definition: Gelatinous layer surrounding some bacteria.
• Difficulty Staining: The capsule is not strongly visible due to the nature of its structure against typical staining methods.

Gram Staining

• Procedure: Specific steps involving crystal violet, iodine, decolorizer (alcohol/acetone), and safranin.
• Gram-Positive: Retain crystal violet; appear purple.
• Gram-Negative: Lose crystal violet and stain red with safranin.
• Basis: Differences in cell wall structures.

Endospores

• Functions: A resting, dormant structure allowing survival under adverse conditions. Resistance to heat, chemicals, etc.
• Producing Genera: Bacillus, Clostridium.
• Staining: Using Schaeffer-Fulton method, spores stain differentially to differentiate them from the vegetative body of the bacteria.

Acid-Fast Staining

• Medical Importance: Differentiate acid-fast bacteria (e.g., Mycobacterium) from non-acid-fast organisms; important for diagnosis.
• Characteristics: Presence of waxy mycolic acid in the cell wall. Resist decolorization.
• Procedure: Use of carbolfuchsin, acid-alcohol to decolorize, and methylene blue as a counterstain.

Motility Determination

• Hanging Drop Method: Direct observation of bacterial movement in a hanging drop of liquid culture medium.
• Tube Method: Observe motility by observing cloudiness in a liquid medium of culture.

Culture Media

• Definition: Nutrient solutions containing specific compounds required for microbial growth.
• Agar: Solidifying agent in culture media.

Microbial Nutrition

• Autotrophs: Obtain carbon from inorganic sources.
• Heterotrophs: Obtain carbon from organic sources.
• Photoautotrophs: Use light for energy, inorganic carbon as a carbon source.
• Chemoautotrophs: Obtain energy from inorganic chemicals, inorganic carbon as a carbon source.
• Chemoheterotrophs: Obtain energy and carbon from organic sources.
• Photoheterotrophs: Use light for energy, organic carbon as a carbon source.
• Growth Factors: Organic compounds required by some bacteria for growth.
• Synthetic Media: Defined chemical composition.
• Non-synthetic Media: Complex, undefined ingredients (examples: blood agar, nutrient agar).

Selective and Differential Media

• Selective Media: Allows growth of specific organisms because it inhibits to select others.
• Differential Media: Allow differentiation of organisms based on their metabolic reactions (e.g., changes in color, gas production).

Autoclaving

• Time and Temperature: Standard autoclaving conditions for sterilization.

Pure Culture Isolation

• Methods: Techniques for isolating pure cultures based on streaking the colonies and selection of single colonies.

Quantitative Plating

• Countable Plate: Plate with a number of colonies that can be readily counted.

Microbial Growth Conditions

• Optimum Temperature: Ideal temperature for growth.
• Maximum Temperature: Highest temperature for growth.
• Minimum Temperature: Lowest temperature.
• Mesophiles: Organisms growing best at moderate temperatures.
• Psychrophiles: Organisms growing best at low temperatures.
• Thermophiles: Organisms growing best at high temperatures.
• Thermal Death Time: Time required to kill all microbes.
• Thermal Death Point: Lowest temperature at which all microbes are killed in a given time.
• Hypotonic, Hypertonic, Isotonic: Solutions differing in solute concentration relative to cells.
• Plasmolysis: Shrinking of cells due to hypertonic solution conditions.
• Osmophiles: Organisms growing best at high osmotic pressure.
• Halophiles: Organisms growing best in high salt concentrations.

Cellular Response to Environments

• Hypotonic: Cells swell and may burst.
• Hypertonic: Cells shrink and lose water.

Antimicrobial Agents

• Antiseptics: Used on living tissues to prevent infection.
• Disinfectants: Used to eliminate microorganisms from inanimate objects.
• Antibiotics: Chemicals produced by microorganisms that kill or inhibit the growth of other microorganisms.

Zone of Inhibition

• Definition: Area around an antibiotic disk where bacterial growth is inhibited.

Kirby-Bauer Method

• Method: Standard procedure for determining the sensitivity or resistance of bacteria to antimicrobial agents.

Microbial Metabolism

• Fermentation: Metabolic process yielding energy under anaerobic conditions.
• Metabolism: All chemical reactions within an organism.
• Endoenzymes: Enzymes acting within the cell.
• Exoenzymes: Enzymes acting outside the cell.
• Oxidation: Loss of electrons.

Biochemical Tests

• Detailed descriptions of media, reagents, expected results, positive reactions. (You'll need to consult individual descriptions of these tests).
  • Durham tube sugar fermentation.
  • Mixed acid fermentation.
  • Butanediol fermentation.
  • Catalase production.
  • Oxidase production.
  • Starch hydrolysis.
  • Casein hydrolysis.
  • Fat hydrolysis.
  • Tryptophan hydrolysis.
  • Urea hydrolysis.
  • Hydrogen sulfide production.
  • Citrate utilization.
  • IMViC test
  • Phenylalanine deamination.

Enzyme Function

• Specific functions relating catalase, urease, amylase, lipase, tryptophanase, (need additional specifics on function)

Additional Notes

• Review figures as specifically stated. Study the appearance of microorganisms and results, and note the correct use of aseptic technique in all procedures.

Test your knowledge on the parts and functions of a compound microscope and the principles of microscopy resolution. This quiz covers key concepts like total magnification, resolving power, and the significance of each component. Perfect for biology students and enthusiasts!