Lecture Notes

Introduction

• Topic: Continuation of Lecture 1 and Introduction to Lecture 2
• Main Discussion: The Three-Domain System of Life

Three-Domain System of Life

• Domains:
  • Bacteria
  • Eukarya
  • Archaea
• Developer of the System: Carl Woese
• Basis: Based on 16S rRNA nucleotide sequence
• Significance: Classification of all living things

Classifying and Naming Microorganisms

• Taxonomic System: Formal taxonomic system
• Originator: Carolus Linnaeus
• Purpose: Orderly classification by morphology, biochemical characteristics, etc.
• Nomenclature: Proper writing of microorganism names, focus on prokaryotes
  • Example: Staphylococcus aureus
    • Genus: Staphylococcus (capitalized)
    • Species: aureus (lowercase)

Writing Names of Microorganisms

• Handwriting: Underline the names (e.g., Staphylococcus aureus or S. aureus)
• Typed: Italics
• Abbreviation: Usually not done initially to avoid confusion

Historical Figures in Microbiology

• Antony van Leeuwenhoek: Discovery of microscopy
• Louis Pasteur: Pasteurization, disproved spontaneous generation
• Robert Koch: Germ theory, Koch's postulates

Spontaneous Generation vs. Biogenesis

• Spontaneous Generation: Life arises spontaneously
• Biogenesis: Life arises from pre-existing life
• Key Experiments:
  • Francesco Redi: Disproved spontaneous generation with meat experiment
  • Lazzaro Spallanzani: Contradicted Needham, sealed flask experiments
  • Louis Pasteur: Swan-necked flask experiment conclusively disproved spontaneous generation

Koch’s Postulates

1. Observation: Same disease symptoms in all cases
2. Cultivation: Organism isolated in pure culture
3. Introduction: Pure culture causes disease in healthy animal
4. Recovery: Same organism isolated from newly diseased animal

• Importance: Links specific organism to specific disease

Chemistry of Microbiology

• Elements in Life: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur (CHONPS)
• Atomic Structure:
  • Electron Shells: Atoms in shells corresponding to energy levels
  • Stability: Full outer shells are chemically stable

HONC Rules

• Hydrogen (H): 1 bond
• Oxygen (O): 2 bonds
• Nitrogen (N): 3 bonds
• Carbon (C): 4 bonds
• Practice: Drawing chemical structures using HONC rules

Functional Groups and Macromolecules

• Functional groups are important for biochemical reactions
• Macromolecules: Carbohydrates, Lipids, Proteins, Nucleic Acids
  • Carbohydrates: Good and bad carbs
  • Lipids: Good and bad lipids
  • Proteins: Essential for body function
  • Nucleic Acids: DNA and RNA
• Homework: Familiarize with functional groups and review material