Introduction to Bioenergetics

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Introduction to Bioenergetics
2014-10-19 17:01:33
Test Two
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  1. Explain the generation of ATP.
    • ATP is generated by the phosphorylation of ADP
    • ADP+ energy+ phosphate> ATP

    Substrate level phosophorylation is the transfer of a high energy PO4- to ADP
  2. Energy released from ___ to __ is used to __ by __.
    • the transfer of electrons (oxidation) of one compound
    • another (reduction)
    • generate ATP
    • chemiosmosis
  3. Aerobic respiration

    Anaerobic respiration
    aerobic: the final electron acceptor in the electron transport chain is molecular oxygen (O2)

    anaerobic: the final electron acceptor in the electron transport chain is not O2. Yields less energy than aerobic respiration because only part of the Krebs cycle operations under anaerobic conditions. Absolute vs. Facultative
  4. Bacteria can undergo __. 

    Not enough or not at all do they have __. __ is bad for them. But, they are capable of doing it.
    aerobic and anaerobic respiration


    protein rich metabolism
  5. What is a big difference between aerobic and anaerobic respiration?
    • anaerobic always yields a lot less. 
    • Can run parts of the Krebs cycle in anaerobic respiration, but does not run the ETC
  6. Absolute anaerobes
    ambient air concentration of O2 or higher is toxic
  7. Facultative anaerobes
    undergo anaerobic respiration but don't care if O2 is present, as long as it is present in small amounts
  8. Carbohydrate catabolism
    the breakdown of carbohydrates to release energy: glycolysis, krebs cycle, and ETC

    By metabolizing glucose, they yield 36-38 ATP molecules

    prokaryotes and eukaryotes are the same in terms of their process
  9. Glycolysis
    final product of glycolysis is two pyruvate molecules, whcih will be coverted to acetyl CoA and be used for the Krebs Cycle

    every organism that respires starts out with glycolysis

    net gain: 2 pyruvates, 2 ATP (originally four but it uses two), and 2 NADH
  10. net gain of the Krebs Cycle
    • generates GTP, 2 FADH2, and 8 NADH
    • 6 CO2 (and 2 ATP)
  11. Locations of the steps.
    glycolysis and the CAC occur in the cytoplasm

    ETC takes place in the inner leaflet of the plasma membrane
  12. What is the energy gain of NADH and FADH2
    • NADH: results in 3 H+, which are pumped back 
    • FADH2: associated with the cytochrome B (1.5)
  13. What are the 3 complexes associated with the ETC?
    1) NADH dehydrogenase: hydrolysis to NAD+ and a proton being pumped

    2) Cytochrome B-C1 with FADH--> H+ and FA

    3) Cytochrome oxidase= another complex that releases 2 Hydrogens
  14. Cellular respiiration
    • oxidation of moelcuels liberates electrons for an ETC 
    • ATP generated by oxidative phosphorylation
  15. What is the location of each pathway in euk and prk?

    intermediate step
    krebs cycle
    glycolysis: cytoplasm, cytoplasm

    intermediate step: cytoplasm, cytoplasm

    krebs cycle: mitochondrial matrix, cytoplasm

    ETC: mitochondrial inner membrane, plasma membrane
  16. What is the big difference between pro and euk?
    • the location
    • the reactions and pKa are all the same
  17. Energy produced from complete oxidation of 1 glucose using aerobic respiration

    • Glycolysis: 2,2,0
    • Intermediate: 0,2
    • Krebs: 2 GTP, 6, 2
    • Total: 4, 10, 2
  18. Alternatives to Glycolysis
    pentose phosphate pathway: 

    entner-Doudoroff pathway
  19. Pentose phosphate pathway:
    • Uses pentoses and NADPH
    • Operates with glycolysis

    uses 5-carbon sugars and turns them into ribose phosphate and ribulose phosphate to get to the pyruvic acid
  20. Entmer-Doudoroff Pathway
    • bacterially defined
    • - produces NADPH and ATP
    • - does not involve glycolysis
    • - Pseudomonas, E. faecalis, E. coli
    • (primary gram negative)
  21. Explain more of the Entmer-Doudoroff pathway
    • 6 carbon sugars
    • one atp per glucose--> 2 atp
    • production of pyruvate from glucose
    • only about 15 bacterial genera/ species use this
  22. Anaerobic respiration

    - Electron acceptor and its products
    NO3- --> NO2-, N2 + H2O

    SO4- --> H2S + H2O

    CO32- --> CH4 + H2O
  23. In anaerobic respiration, everything but __ is the __. 

    Every bacteria taht can undergo these processes are __. They're all __.
    • oxygen 
    • electron acceptor

    • specific 
    • unique products
  24. Fermentation
    releases energy from oxidation of organic molecuels

    does not require oxygen

    does not use the Krebs cycle or the ETC

    uses an organic molecule as the final electron acceptor

    many species have their own

    4 and 5 cycles

    alway less than 38 ATP produced

    could be 8 or 10
  25. Alcohol fermentation
    produces ethyl alcohol and CO2
  26. Lactic acid fermentation
    produces lactic acid

    • homolactic: produces lactic acid only
    • heterolactic: produces lactic acid and other compounds

    most bacteria undergo heterolactic acid fermentation; some water, some CO2
  27. Lipid metabolism
    classic glycerol formation

    34 ATPs

    skips glycolysis completely
  28. Breakdown of proteins yields somewhere below __.
    38 ATP
  29. Anaerobic cycle gives __ ATPs.
  30. Protein catabolism
    protein ----(extracellular proteases)--> amino acids

    -------(deamination, decarboxylation, dehydrogenation, desulfurization)----> organic acid----> krebs cycle
  31. Chemoautotrophy
    bacteria that break down organic minerals in the environment

    breaking up waste

    classic saprophyte qualities

    bacteria are the only species to do this: many are archaea, with exception of one thing, they are not known to pathogens

  32. Chemolithotrophy
    • use oxygen as the final electron acceptor
    • use inorganic compounds as a donor
    • oxidize large amounts of nitrogen, sulfur, and iron containing compounds

    important for cycling nitrogen and sulfur between air, water, and soil

    waste products: methane, water, O2, acetate
  33. Photoautrophy
    • use sunlight to drive ATP production
    • oxygenic: uses water as the electron donor
    • anoxygenic: use H2 and H2S as the electron donor; no O2 produced as a water gas; do not produce oxygen or water as a waste gas

    Mg core= important for electron cycling through the molecule