Microbial Metabolism (CH. 5)

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  1. When are organic molecules oxidized?
    during respiration
  2. Where is energy generated from?
    the electron transport chain
  3. What is the final/terminal electron acceptor in aerobic respiration?
  4. What is the terminal electron acceptor in anaerobic respiration?
    sulfate, carbonate, phosphate
  5. In cellular respiration from one molecue glucose, oxidaion produces how many molecules of the following:
    • 6 molecules NADH
    • 2 molecules FADH2
    • 2 molecules ATP
  6. How are electrons brought to the electron transport chain?
  7. In aerobic prokaryotes how many ATP molecules can be produced from complete oxidation of glucose molecule in glycolysis, the Krebs cycle, and the electron transport chain?
    38 ATP
  8. In (aerobic) eukaryotes how many ATP molecules can be produced from complete oxidation of glucose molecule in glycolysis, the Krebs cycle, and the electron transport chain?
    36 ATP
  9. What is the end-product of glycolysis?
    Pyruvic acid
  10. What are the two major types of glucose catabolism? Describe each.
    Cellular respiration, in which glucose is completely broken down and fermentation, in which it is partially broken down
  11. What are enzymes?
    proteins, produced by licing cells, that catalyze chemical reactions by lowering the activation energy.
  12. What happens to enzyme at high temperature?
    Enzyme undergo denaturation and lose their catalytic properties.
  13. What happen to enzymes at low temperature?
    The reaction rate decreases.
  14. Where is most of cell's energy produced?
    from the oxidation of carbohydrates
  15. What is the most commonly used carbohydrate?
  16. How many ATP and NADH molecules are produced from one glucose molecule?
    • 2 ATP
    • 2 NADH
  17. Catabolism
    refers to the chemical reactions that result in the breakdown of more complex organix molecules into simpler substance. 
  18. Anabolism
    refers to chemical reactions in which simpler substance ar combined to form more complex molecules
  19. Where is the energy for chemical reaction stored in?
  20. What is the conversion of light energy from the sun into chemical energy? What is the chemical energy used for?
    • Photosynthesis
    • the chemical energy is used for carbon fixation
  21. Define metabolism.
    the sum of all chemical reactions within a living organism
  22. What are 2 reactions of metabolism?
    catabolism and anabolism
  23. What are the components of an enzyme?
    cofactor (or coenzyme; if cofactor is organic) & apoenzyme.
  24. What happens if the the cofactor is removed from a holoenzyme?
    the apoenzyme will not function
  25. What are the two most important coenzymes in cellular metabolism? What does both compound contain and its function?
    • NAD+ (nicotinamide adenine dinucleotide)
    • NADP+ (nicotinamide adenine dinucleotide phosphate)

    both compound contain derivatives of the B vitamins niacin ( nicotinic acid). both function as electron carriers: NAD+ catabolic (energy-yielding) and NADP+ is primarily involved in anabolic reactions (energy-requiring)
  26. What are flavin coenzymes? What does in contain and its function?
    • FMN (flavin mononucleotide)
    • FAD (flavin adenine dinucleotide)
    • contain derivatives of the B vitamins riboflavin, function as electron carriers
  27. What is coenzyme A (CoA)?
    a coenzyme that contains a derivative of pantothenic acid, another B vitamin.  CoA plays and important role in the synthesis and breakdown of fats and in a series of oxidizing reactions called the Krebs cycle.
  28. Define the following:
    (2)active site
    (3)enzyme-substrate complex
    • 1. any compound with which an enzyme reacts
    • 2. a region on an enzyme that interacts with the substrate
    • 3. a temporary union of an enzyme and its substrate
  29. factors that influence enzyme activity
    • 1. At high temperatures, enzymes undergo denaturation and lose their catalytic properties; at low temperatures, the reaction rate decreases.
    • 2. The pH at which enzymatic activity is maximal is known as the optimum pH.
    • 3. Within limits, enzymatic activity increases as substrate concentration increases.
    • 4. Competitive inhibitors compete with the normal substrate for the active site of the enzyme. Noncompetitive inhibitors act on other parts of the apoenzyme or on the cofactor and decrease the enzyme's ability to combine with the normal substrate by altering the shape of the active site.
  30. What is phosphorylation?
    Energy released during certain metabolic reactions can be trapped to form ATP from ADP and P (a single phosphate ion). Addition of P to a molecule 
  31. List and provide examples of three types of phosphorylation reactions that generate ATP
    • substrate-level phosphorylation, a high-energy P from an intermediate in catabolism is added to ADP. 
    • oxidative phosphorylation, energy is released as electrons are passed to a series of electron acceptors (an electron transport chain) and finally O2 or another inorganic compound.
    • photophosphorylation, energy from light is trapped by chlorophyll, and electrons are passed through a series of electron acceptors. The electron transfer releases energy used for the synthesis of ATP.
  32. what is oxidation-reduction?
    Explain what is meant by oxidation-reduction
    a coupled reaction in which one substance is oxidized and one is reduced

    • 1. Oxidation is the removal of one or more electrons from a substrate. Protons (H+) are often removed with the electrons.
    • 2. Reduction of a substrate refers to its gain of one or more electrons.
    • 3. Each time a substrate is oxidized, another is simultaneously reduced.
    • 4. NAD+ is the oxidized form; NADH is the reduced form.
    • 5. Glucose is a reduced molecule; energy is released during a cell's oxidation of glucose.
  33. Describe the mechanism of enzymatic activity
    When an enzyme and substrate combine, the substrate is transformed, and the enzyme is recovered. Enzymes are characterized by specificity, which is a function of their active sites.
  34. competitive inhibitors
    fill the active site of an enzyme and compete with the normal substrate for the active site. this is possible because its shape and chemical structure are similar to those of the normal substrate
  35. noncompetitive inhibitors
    do not compete with the substrate for the enzyme's active site; instead, they interact with another part of the enzyme
  36. feedback inhibition
    inhibition of an enzyme in a particular pathway by the accumulation of the end-product of the pathway; also called end-product inhibition

    stops the cell form making more of a substance than it needs and thereby wasting chemical resources

    acts on the first enzyme in a metabolic pathway

Card Set
Microbial Metabolism (CH. 5)
ATP, metabolism, fermentation, glycolysis, Kreb cycle, electron transport chain
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