Intro

Page 1

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Page 2: Microbial Development and Taxonomy

• Early Development of Microbiology:

  • Study of microbes began with the invention of the microscope.

  • Key historical texts and chapters in microbiology (Chapters 1-4).

• Key Terminology:

  • Clear vs. Cloudy: Indications of bacterial growth.

    • Clear: No growth

    • Cloudy: Presence of microorganisms

  • Sterile: Free of all living forms, crucial for laboratory conditions.

Page 3: Introduction to Microbiology

• Microbiology Defined:

  • The study of microscopic organisms (microbes) prevalent in various environments.

• Importance of Microbes:

  • Essential for digestion (e.g., probiotics) and production of insulin.

  • Decomposers play a vital role in nutrient cycling.

  • Some microbes can be harmful, causing food spoilage and diseases.

• Bacterial Shapes:

  1. Coccus: Round shape

  2. Bacillus: Rod shape

  3. Spirillum: Spiral shape

• Historical Contributions:

  • Aristotle (346 BC): Early thoughts on life.

  • Francesco Redi (1665): Disproved spontaneous generation.

  • Louis Pasteur: Key contributions to germ theory and disproving spontaneous generation.

  • Robert Koch: Formulated Koch's postulates, establishing principles for linking bacteria to diseases.

    • Koch's Postulates:

      1. Pathogen present in every case.

      2. Isolated from diseased host.

      3. Causes disease in healthy subject.

      4. Re-isolated from subject and identical.

Page 4: The Carbon Cycle

• Carbon's Significance:

  • Makes up 96.2% of human body.

  • Serves as the backbone for organic compounds like carbohydrates, lipids, proteins, and nucleic acids.

• Carbon Atom Structure:

  • 6 Protons, needs 4 bonds forming stable compounds.

• Carbon in Nature:

  • Present as CO2 primarily in the atmosphere and oceans.

  • Processes involved in the carbon cycle:

    1. Photosynthesis: Removes CO2 from the atmosphere.

    2. Cellular Respiration: Returns CO2 back to the atmosphere.

    3. Combustion of fossil fuels contributes additional CO2.

Page 5: Carbon Cycle Overview

• Processes of the Carbon Cycle:

  1. Photosynthesis: Converts CO2 to glucose, removing CO2 from the atmosphere.

  2. Cellular Respiration: Converts glucose back to CO2 and energy.

  3. Combustion: Involves burning fossil fuel and returning CO2.

• Importance of Nitrogen Cycle:

  • Nitrogen fixation: Conversion of atmospheric nitrogen into ammonia.

    • Carried out by bacteria (e.g., Rhizobium).

  • Nitrification: Conversion of ammonia to nitrates, necessary for organic use.

  • Assimilation and Ammonification: Releasing nitrogen from decomposition and incorporation into living tissues.

Page 6: Nitrogen Cycle Details

• Ammonification:

  • Conversion of organic nitrogen in wastes/decomposed matter back to ammonia.

• Denitrification:

  • Conversion of nitrates back to nitrogen gas, released into the atmosphere by denitrifying bacteria (e.g., Pseudomonas).

Page 7: Taxonomy

• Classification of Life:

  • Formal system organizing living things into various taxa (groups).

  • Levels of Classification:

    1. Specimen

    2. Genus

    3. Family

    4. Order

    5. Class

    6. Phylum

    7. Kingdom

  • Three Domains:

    • Archaea

    • Bacteria

    • Eukarya

• Binomial Nomenclature System:

  • Two-part naming system for species.

    • Genus name (capitalized) + species name (lowercase), both italicized (e.g., Escherichia coli).

  • Examples: Named after discoverer or based on characteristics.

Page 8: Associations Between Organisms

• Symbiotic Relationships:

  • Types include:

    1. Mutualism: Both partners benefit (e.g., Rhizobium in legumes).

    2. Commensalism: One benefits, the other unaffected.

    3. Parasitism: One benefits at the expense of the other.

• Non-symbiotic Relationships:

  • Synergism: Increased effect when organisms exist together (e.g., gum disease).

  • Antagonism: Competition where one organism inhibits another utilizing resources.

• Bacterial Shapes Revisited:

  1. Cocci: coccus in clusters (e.g., Staphylococcus aureus).

  2. Bacilli: rod-shaped, includes diplobacillus.

  3. Spirilla: spiral shape that moves by rotation.