Microbial metabolism

• What is an enzyme?

  A biological catalyst that initiates and accelerates chemical reactions without being a reactant.
• What are the main components that form most enzymes?

  Most enzymes are proteins formed from 20 natural amino acids.
• Under what conditions do enzymes typically act?

  Enzymes act under special environmental conditions of temperature and pH.
• How is an enzyme's name derived?

  An enzyme's name is derived from its action and substrate.
• What do proteolytic enzymes act on?

  Proteolytic enzymes act on proteins.
• What do lipolytic enzymes act on?

  Lipolytic enzymes act on lipids.
• What is the function of exoenzymes?

  Exoenzymes are secreted by cells and function outside these cells.
• Why are exoenzymes important for bacteria?

  They aid in nutrient acquisition or dissolving structural materials.
• What are endoenzymes?

  Enzymes that act within the cell.
• Which organism produces α-Amylases as endoenzymes?

  Bacillus subtilis produces α-Amylases.
• What is the role of β-glucanases and hemicellulases produced by Trichoderma reesei?

  They are involved in enzymatic cellulose degradation.
• How are enzymes classified according to diffusibility?

  • Constitutive Enzymes: Produced constantly and independently of the substrate.
  • Adaptive Enzymes: Latent enzymes that become active in the presence of the substrate.
• What is the definition of metabolism?

  Metabolism is the sum of all chemical reactions that occur in the cell.
• What are the two main types of metabolism?

  • Catabolism: Breakdown of complex molecules into simple ones.
  • Anabolism: Synthesis of complex molecules from simple ones.
• What occurs during a reduction-oxidation (redox) reaction?

  One substance gets reduced while another substance gets oxidized.
• What is the electron donor in a redox reaction?

  The substance that gets oxidized.
• What is the electron acceptor in a redox reaction?

  The substance that gets reduced.
• What does oxidation refer to in a chemical reaction?

  Oxidation refers to the loss of hydrogen and/or electrons.
• What does reduction refer to in a chemical reaction?

  Reduction refers to the gain of hydrogen and/or electrons.
• What is ATP and its role in cellular reactions?

  ATP is the "energy currency" for many cellular reactions.
• What is the process of ATP hydrolysis?

  ATP hydrolysis is used as an energy source in many biological reactions.
• What is the equation for ATP hydrolysis?

  ATP + H2O → ADP + Phosphate + Energy (7.5 kcal/mol)
• What are the main stages of aerobic cellular respiration?

  1. Glycolysis: Oxidation of glucose into 2 molecules of pyruvic acid.
  2. Kreb’s Cycle: Series of reactions beginning and ending with citric acid.
  3. Electron Transport Chain: Transfers electrons from donors to acceptors via redox reactions.
• What is the total ATP production from the complete oxidation of one molecule of glucose in aerobic respiration?

  38 ATP
• What is fermentation?

  Fermentation is an anaerobic metabolic process converting sugar to acids, gases, and/or alcohol.
• What are the types of fermentation?

  • Lactic Acid Fermentation
  • Alcohol Fermentation
  • Acetic Acid Fermentation

  
• What is an enzyme?

  A biological catalyst for chemical reactions
• How are most enzymes formed?

  From 20 natural amino acids in cells
• What are proteolytic enzymes responsible for?

  Acting on proteins
• What do lipolytic enzymes act on?

  Lipids
• What is the function of exoenzymes?

  They function outside the cells
• What do exoenzymes help degrade?

  Insoluble polymers in the environment
• What type of enzymes are α-Amylases?

  Endoenzymes
• What is the role of β-glucanases produced by Trichoderma reesei?

  They act as exo- and endo-enzymes
• What is the classification of constitutive enzymes?

  Produced constantly and independently of substrate
• What are adaptive enzymes?

  Enzymes that become active in the presence of substrate
• What are the two main types of metabolism?

  Catabolism and anabolism
• What is metabolism defined as?

  The sum of all chemical reactions in a cell
• What occurs during catabolism?

  Complex molecules are broken down
• What occurs during anabolism?

  Simple molecules are built into complex molecules