Skip to main content
Back

Microbiology Exam I Key Concepts

Control buttons has been changed to "navigation" mode.
1/29
  • Koch's postulates
    A set of criteria to establish a causative relationship between a microbe and a disease.
  • Gram stain purpose
    Differentiates bacteria into Gram-positive and Gram-negative based on cell wall structure.
  • Difference between prokaryotes and eukaryotes
    Prokaryotes lack a nucleus and membrane-bound organelles; eukaryotes have both.
  • Role of Pasteur in microbiology
    Disproved spontaneous generation and developed pasteurization.
  • Major macromolecules in cells
    Lipids, carbohydrates, proteins, and nucleic acids.
  • Function of ATP
    ATP is the main energy currency of the cell.
  • Types of chemical bonds important in biology
    Covalent, ionic, hydrogen bonds, and van der Waals forces.
  • Hydrogen bond significance
    Stabilizes protein and nucleic acid structures and affects water properties.
  • Dehydration synthesis
    A chemical reaction that joins monomers by removing water.
  • Function of buffers in cells
    Maintain pH stability by neutralizing acids or bases.
  • Bacterial cell wall composition
    Made primarily of peptidoglycan, varying between Gram-positive and Gram-negative bacteria.
  • Difference between Gram-positive and Gram-negative walls
    Gram-positive have thick peptidoglycan; Gram-negative have thin peptidoglycan and an outer membrane.
  • Function of glycocalyx
    Protects cells and helps in attachment; includes capsules and slime layers.
  • Purpose of bacterial flagella
    Enable motility.
  • Role of pili
    Facilitate attachment and conjugation between bacteria.
  • Endospores
    Dormant, resistant structures formed by some bacteria for survival.
  • Endosymbiotic theory
    Eukaryotic organelles like mitochondria originated from prokaryotic cells.
  • Microscopy magnification vs. resolution
    Magnification enlarges image; resolution distinguishes two close points.
  • Bright-field vs. dark-field microscopy
    Bright-field uses light through specimen; dark-field shows light scattered by specimen.
  • Difference between TEM and SEM
    TEM shows internal structures; SEM shows surface details.
  • Basic vs. acidic dyes
    Basic dyes stain cells (positive charge); acidic dyes stain background (negative charge).
  • Binomial nomenclature
    Two-part naming system for organisms: genus and species.
  • Role of LPS (endotoxin)
    Component of Gram-negative outer membrane that can trigger immune responses.
  • Osmosis in cells
    Movement of water across a membrane from low to high solute concentration.
  • Active transport
    Energy-dependent movement of substances against their concentration gradient.
  • Protein shape importance
    Determines protein function and is stabilized by hydrogen bonds.
  • Chemical structure of DNA vs. RNA
    DNA has deoxyribose sugar and thymine; RNA has ribose sugar and uracil.
  • Public health impact of microbiology
    Understanding microbes helps control infectious diseases and improve sanitation.
  • Magic bullet concept
    A targeted antimicrobial agent that kills pathogens without harming the host.