Bio1151b Chapter 9 Cellular Respiration: Harvesting Chemical Energy
  1. Living organisms require         to perform cellular work. Energy flows into most ecosystems as           and leaves as       .
     
     
  2. Cellular              is a catabolic pathway that consumes         and organic molecules and yields the energy molecule      by the transfer of            .
     
     
  3. Electron transfer occurs through chemical reactions called        reactions. Molecules such as NAD+ and FAD act as electron receptors in this pathway.
     
     
  4. In cellular respiration,          is oxidized and         is reduced, in a series of steps called the           transport chain (ETC) to form      .
     
     
  5. Cellular respiration comprises three metabolic stages: glycolysis, citric acid cycle, and oxidative phosphorylation.
       
       
    •             occurs in the          to produce two molecules of      from the metabolism of one          molecule.
       
       
    • The           is converted to         CoA, which enters the         acid cycle in the matrix of the mitochondrion.
       
       
    • During            phosphorylation, NADH and FADH2 donate            to the ETC to produce about 32 to 34 molecules of ATP.
     
     
    Review: Cellular Respiration
     
     
  6. In            conditions, glycolysis is followed by               , which does not produce      , but regenerates NAD+, and allows glyocolysis to continue generating      .
     
     
  7. Other organic molecules such as           and       can also enter cellular respiration via different            pathways.