microbiology final ch. 5, 6, & 7

• Carbohydrate Catabolism


  The process that cells break down glucose to produce ATP.
• Glycolysis


  1. Input: Glucose, 2 ATP, 2 NAD+

  2. Output: 2 pyruvate, 4 ATP, 2 NADH
• Intermediate Step


  1. Input: 2 pyruvate, 2 Coenzyme A, 2 NAD+

  2. Output: 2 Acetyl-CoA, 2 CO2, 2 NADH
• Kreb's Cycle


  1. Input: 2 Acetyl-CoA

  2. Output: 4 CO2, 6 NADH, 2 FADH, 2 ATP
• Electron Transport Chain


  1. Input: NADH, FADH, O2

  2. Output: H2O, ATP
• ATP

  Utilized for cellular work, active transport, and metabolic processes. It is essential for energy-requiring processes in cells.
• Psychrophile

  • Cold-loving; -10-20ºC
• Psychrotrophs

  • 10-30ºC; cause food spoilage
• Mesophiles


  • 25-30ºC; most common spoilage and disease organisms
• Thermophiles

  • 50-60ºC; important for compost piles
• Hyperthermophiles

  • >80ºC; live in hot springs; use sulfur as metabolism source
• Bacteria

  • Grow between 6.5-7.5 pH
• Molds and yeasts

  • Grow between 5.5-6.5 pH
• Acidophiles

  • Grow in acidic environments
• Hypertonic environments

  • Cause plasmolysis due to high osmotic pressure
• Extreme or obligate halophiles

  • Tolerate high osmotic pressure (high salt)
• Facultative halophiles


  • Tolerate high osmotic pressure
• Aerobic organisms

  • Use oxygen as final electron acceptor, allow for more energy production
• Oxygen

  • Can have toxic forms that harm cells
• Biofilms

  Communities that adhere to the surface to function together
• Bacterial Growth Curve

  1. Lag Phase: Preparing for population growth

  2. Log Phase: Exponential increase in population due to reproduction

  3. Stationary Phase: Balancing period, microbial deaths balance new cell production

  4. Death Phase: Population decreasing rapidly
• Microbial control agents

  Can kill/inhibit growth by altering membrane permeability, damaging proteins, or damaging nucleic acids
• Moist Heat Sterilization Techniques

  • Boiling
  • Autoclaving
  • Pasteurization
• Boiling

  Kills all vegetative forms of bacteria within 10 minutes
• Autoclaving

  Most effective, kills all organisms including endospores in 15 minutes
• Pasteurization

  Reduces spoilage of organisms and pathogens
• Dry Heat Sterilization Techniques

  • Incineration
  • Flaming
  • Hot air
• Incineration

  Used for disposing of contaminated waste
• Flaming

  Used for inoculating loop in lab
• Hot air

  170ºC for 2 hours
• Ionizing radiation

  Damages DNA by causing lethal mutations, used to sterilize food, medical equipment, and mail
• Non-ionizing radiation

  Damages DNA by creating thymine dimers, disinfects medical products & vaccines, can cause eye damage or even cancer