Oxidative Phosphorylation

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  1. a.      After the CAC, molecules of __ account for most of the energy extracted from glucose
                                                                  i.      These electron escorts link__, which powers ATP synthesis through __
    • NADH and FADH2
    •  glycolysis and the CAC to the ETC
    • energy release
  2. a.      ETC
                                                                  i.      What is it?
                                                                ii.      Cristae do what?
    1.      Most components are __, which exist in __
    a.      Bound to these are __, nonprotein components essential for the catalytic functions of certain enzymes
    • Collection of molecules in the inner membrane of the mitochondria (euk.) or plasma membrane (pro.)
    •  increase surface area, allowing several ETCs
    • proteins
    • multiprotein complexes numbered I through IV
    • prosthetic groups
  3.                                                               i.      During electron transport, carriers alternate between __ and __ states
    reduced and oxidized
  4.                                                               i.      Complex I:
    1.      Electrons are transferred from __to the first molecule of the ETC in complex I, a __.
    a.      Explain the progression.
    • NADH
    • flavoprotein
    • Flavoprotein--> iron-sulfur protein--> ubiquitone (not a protein, but a small hydrophobic molecule)--> cytochromes whose prosthetic group (heme group) has an iron atom that accepts and donates electrons--> cytochrome a3--> oxygen
  5. 1.      FADH adds its electrons to the ETC within __, at a __energy level than NADH
    a.      As a result, even though they both donate the same amount of electrons, the ETC provides __energy for ATP when FADH2 is the donor
    • complex II
    • lower
    • 1/3 less
  6. Purpose of ETC
    • makes no ATP directly
    • instead, it eases the fall of electrons from food to oxygen
  7. a.      Chemiosmosis
                                                                  i.      In the inner membrane are __, enzymes that make ATP from ADP and inorganic phosphate
    1.      Under the conditions of respiration, ATP synthase uses the energy of an __ to power ATP synthesis
    a.      Power source is a __
                                                                                                                                          i.      This process, in which energy is stored in the form of a hydrogen ion gradient across a membrane is used to drive cellular work such as the synthesis of ATP, called __
    • ATP synthases
    • existing ion gradient
    • difference in the concentration of H+ on opposite sides of the inner mitochondrial membrane
    • chemiosmosis
  8.                                                               i.      ATP Synthase
    1.      Multi-subunit complex with __main parts, each made of multiple polypeptides
    a.      Protons move one by one into binding sites on one of the parts (the __) , causing it to __
    • four
    • rotor
    • spin in a way that catalyzes ATP production
  9. What is a major function of the ETC?
    establishing the H+ gradient

    •  1.      It uses the exergonic flow of electrons from NADH and FADH2 to pump H+ across the membrane from the mitochondrial matrix into the intermembrane space
    • a.      H+  has a tendency to diffuse down gradient; only way is through ATP synthases
  10. 1.      The energy stored in an H+ gradient across a membrane couples the __ 
    2.      How does the ETC pump hydrogen ions?

    a.      In eukaryotes, the electron carriers are spatially arranged in the inner membrane in such a way that __
    • redox reactions of the ETC to ATP synthesis
    • The ETC pumps hydrogen ions by certain members of the ETC that accept and release both protons and electrons at certain steps
    • H+ is accepted from the mitochondrial matrix and deposited in the intermembrane space
  11.                                                                                                                                       i.      H+ gradient is referred to as a__, emphasizing the capacity of the gradient to perform work
    1.     What does the force do>
    •  proton-motive force,
    •  The force drives H+ back across the membrane through the H+ channels provided by ATP synthases
  12.                                                               i.      In general, what is chemiosmosis?
    1.      Energy for gradient formation: __
    ATP synthesis is the work performed
    • chemiosmosis is an energy-coupling mechanism that uses energy stored in the form of an H+ gradient across a membrane to drive cellular work
    • exergonic redox reactions
  13.                                                               i.      Occurs in other places too
    1.      Chloroplasts use chemiosmosis to__
    a.      __rather than __drives both __ and the__
    •  generate ATP during photosynthesis
    • Light
    • chemical energy
    • electro flow down an ETC
    •  resulting H+ gradient formation
  14. 1.      Prokaryotes generate __ across their membranes
    a.      They then tap the __to generate ATP and move flagella and pump nutrients and waste across the membrane 
    • H+ gradients
    • proton-motive force

Card Set Information

Oxidative Phosphorylation
2012-11-11 13:39:04
Exam III cell resp

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