Fermentation and Anaerobic Respiration

  1. a.      ATP yield of aerobic respiration is contingent on adequate supply of __, without which __ would cease
                                                                  i.      This is solved by __= without oxygen
    1.      Distinction between the two: __
    • oxygen
    • oxidative phosphorylation
    • fermentation and anaerobic respiration
    • ETC used in anaerobic, not fermentation
  2. a.      Anaerobic Respiration
                                                                  i.      Takes place in certain prokaryotes that live without oxygen
    1.      __is used, but instead of oxygen as final acceptor, __, __, can do the job
    a.      Instead of __as byproduct, other substance produced, such as H2S
    • ETC
    • other electronegative substances;such as sulfate ion
    • H2O
  3. a.      Fermentation: __+ reactions that __ by __ to __
    • glycolysis
    • regenerate NAD+
    • transferring electrons from NADH
    • pyruvate or its derivatives
  4.                                                               i.      Harvests energy without __or __
    1.      Glycolysis oxidizes glucose to __a.      Oxidizing agent of glycolysis is __
    b.      It is __, and some of the energy made available makes ATP through __
    c.       Glycolysis generates __ regardless of oxygen’s presence
    • oxygen
    • ETC
    • two molecules of pyruvate
    • NAD+
    • exergonic
    • substrate-level phosphorylation
    • two ATP
  5.                                                               i.      It is an extension of glycolysis that allows continuous generation of ATP by the __
    1.      There must be a sufficient supply of__ to accept electrons during the __ step of glycolysis
    a.      Without recycling of NAD+ from NADH, what would happen?
    • substrate-level phosphorylation of glycolysis
    •  NAD+
    • oxidation
    •  glycolysis would reduce all NAD+, depleting its pool, and shut itself down 
  6. Types of Fermentation
    alcohol and lactic acid fermentation
  7. Explain alcohol fermentation
    • Pyruvate--> ethanol in two steps
    • 1: release of CO2 from pyruvate, which is converted to acetaldehyde
    • 2: acetaldehyde reduced by NADH to ethanol, regenerating NAD+
  8. Explain lactic acid fermentation
    pyruvate reduced directly by NADH to form lactate with no CO2 release
  9. a.      Humans do __when oxygen is scarce
                                                                                                                                          i.      Exercise
                                                                                                                                        ii.      Excess lactase is carried by blood to __, where its converted __
    • lactic acid fermentation
    • liver
    • back to pyruvate
  10. Comparison of Fermentation with Anaerobic and Aerobic REspiration
    • 1.      All three use glycolysis to oxidize glucose and other organic fuels to pyruvate, producing two ATP by substrate level phosphorylation
    • 2.      NAD+ is oxidizing agent
  11. Contrast: __
    1.      Contrasting mechanisms for oxidizing NADH back to NAD+

    • a.      F: final electron acceptor is organic molecule, such as pyruvate or acetaldehyde
    • b.      CR: electrons in NADH transferred to ETC, where they move down to a final electron acceptor
    • - Aerobic: oxygen/ Anaerobic: electronegative molecule
  12. The passage of electrons down an ETC allows __?
    ATP production and NAD+ regeneration and more ATP from oxidation of pyruvate iin the mitochondria
  13. Without an ETC, what is up?
    energy stored in pyruvate is unavailable
  14.                                                                                                                                       i.      Cellular Respiration harvests more energy than fermentation (__x more)
  15. Types of Organisms:
    Obligate anaerobes: __
    1.      Carry out only fermentation or anaerobic respiration and can’t survive in presence of oxygen 

  16. Types of Organisms:
    Facultative anaerobes:__
    • 1.      carry out only aerobic oxidation of pyruvate, not fermentation or respiration (cells of the brain)
    • a.      muscle cells can do this
    •                                                                                                                                       i.      pyruvate is a fork in the road that has two ways
    • 1.      aerobic: pyruvateà acetyl CoAà CAC
    • 2.      anaerobic: lactic acid fermentation
    • a.      pyruvate becomes electron acceptor to recycle NAD+
  17. a.      Evolution
                                                                  i.      __is evolutionary
    1.      Ancient prokaryotes used __before oxygen was present
    2.      It evolved with presence of __
    3.      Location in __implies great antiquity because it doesn’t require membrane
    • Glycolysis
    • glycolysis
    • oxygen
    • cytosol
Card Set
Fermentation and Anaerobic Respiration