Citric Acid Cycle

  1.                                                               i.      Functions as a metabolic furnace that __ organic fuel derived from __
                                                                ii.      Generates __ ATP per turn by __, but most of the chemical energy is transferred to __ and a related electron carrier, the coenzyme __during the __
    1.      The reduced coenzymes, __, do what?
    • oxidizes
    • pyruvate
    • 1
    • substrate-level phosphorylation,
    • NAD+
    • FAD
    • redox reactions
    • NADH and FADH2
    • shuttle their cargo of high-energy electrons to the ETC
  2.                                                               i.      For each turn of the CAC,__s enter in the __form of an __group and two different __leave in __
    •  two carbon
    • reduced
    • acetyl
    • carbons
    • oxidized CO2
  3. What are the eight steps?
    • 1.      Acetyl CoA adds two- carbon acetyl to oxaloacetate, forming citrate
    • 2.      Citrate converted to isocitrate by removal of one water molecule and addition of another
    • 3.      Isocitrate is oxidized by NAD+, which becomes NADH. CO2 is lost
    • 4.      Another CO2 is lost and the resulting compound is oxidized, reducing NAD+.
    • 5.      CoA is displaced by a phosphate group, which is transferred to GDP, forming GTP
    • 6.      Two hydrogens are transferred to FAD, forming FADH2
    • 7.      Addition of a water rearranges substrates’ bonds
    • 8.      Substrate is oxidized, reducing NAD+, regenerating oxaloacetate
  4. Summary of CAC
                                                                  i.      Summary of steps: Acetyl group of acetyl CoA joins the cycle by combining with the compound oxaloacetate and the next seven steps decompose the citrate back to oxaloacetate, regenerating it and thus making it a cycle
  5. Output of the cycle
    • 1.      For each acetyl group=
    • a.      3 NADHà 6
    • b.      1 FADH2à2
    • c.       1 GTP, which can be directly used or used to make ATPà2 ATP
Card Set
Citric Acid Cycle