Microbial Metabolism

• What is metabolism?


  All chemical reactions within a living organism
• What are the two main types of metabolism?

  • Catabolism: breakdown of complex molecules, releases energy
  • Anabolism: building of complex molecules, requires energy
• What is catabolism?

  Breakdown of complex organic molecules
• What does catabolism release?

  Energy
• What is anabolism?

  Building of complex organic molecules
• What does anabolism require?

  Energy
• What are enzymes?

  Catalysts that speed up chemical reactions
• Why are enzymes substrate specific?

  They only catalyze specific reactions
• What do lipases act on?

  Lipids
• What do sucrases act on?

  Sucrose
• What do ureases act on?

  Urea
• What do proteases act on?

  Proteins
• What do DNases act on?

  DNA
• How are most enzymes named?

  By adding “ase” to the substrate
• What is the enzyme for sucrose?

  Sucrase
• What is the enzyme for lipids?

  Lipase
• What is the enzyme for DNA?

  DNase
• What is the enzyme for proteins?


  Protease
• What does dehydrogenase remove?


  A hydrogen
• What does phosphatase remove?


  A phosphate
• How are enzymes grouped?

  • Based on the type of reaction they catalyze:

  1. Oxidoreductases: oxidation & reduction
  2. Hydrolases: hydrolysis
  3. Ligases: synthesis
• What are the components of an enzyme?

  • Apoenzyme: protein portion
  • Coenzyme (cofactor): non-protein
  • Holoenzyme: whole enzyme
• What are coenzymes derived from?

  Vitamins
• What is NAD derived from?

  Niacin
• What is FAD derived from?

  Riboflavin
• What is Coenzyme A derived from?

  Pantothenic acid
• What factors influence enzymatic activity?

  • Denaturation of an active protein
• What does oxidation refer to?

  Loss of hydrogens or electrons
• What does reduction refer to?

  Gain of hydrogens or electrons
• What is the NAD cycle?

  • Involves oxidation and reduction processes
  • Key in energy production
• What is carbohydrate catabolism?

  • Microorganisms oxidize carbohydrates for energy
  • Glucose is the most common energy source
• What are the two processes to obtain energy from glucose?

  Respiration and fermentation
• What is aerobic cellular respiration?

  • Electrons released by oxidation pass down an Electron Transport System
  • Oxygen is the final electron acceptor
• What is the general equation for aerobic cellular respiration?

  Glucose + oxygen → CO2 + water + ATP
• What are the four subpathways of aerobic cellular respiration?

  1. Glycolysis
  2. Transition Reaction
  3. Krebs Cycle
  4. Electron Transport System
• What occurs during glycolysis?

  Oxidation of glucose into 2 pyruvic acid
• What are the end products of glycolysis?

  2 pyruvic acid, 2 NADH2, 2 ATP
• What is the transition reaction?

  • Connects glycolysis to Krebs Cycle
  • End products: 2 acetyl CoA, 2 CO2, 2 NADH2
• What is the Krebs Cycle?

  • Series of reactions beginning and ending with citric acid
  • Products: 2 ATP, 6 NADH2, 2 FADH2, 4 CO2
• What occurs in the Electron Transport System?

  • Occurs within the cell membrane of bacteria
  • Produces 34 ATP