CELL RESPIRATION 1977:				L. PETERSON/AP BIOLOGY
	Explain how the molecular reactions of cellular respiration transform 
	the chemical bond energy of Krebs Cycle substrates into the more readily 
	available bond energy of ATP. Include in your discussion the structure 
	of the mitochondrion and show how it is important to the reactions of the 
	Krebs Cycle and the Electron Transport Chain.

  
  STANDARDS:   1/2 point for each of the following
  ___Krebs and ETS occur within mitochondria
  ___Krebs - enzymes freely present in matrix fluid
  ___ETS - respiratory chain (respiratory assembly) arranged in order
         inner membrane of mitochondria (Diagram OK)
  ___more active cells - more respiratory assemblies & more cristae
  ___Aerobic - O2 necessary as final H acceptor (-> H2O)
     (most eukaryotic cells all of the time)
  ___Glycolysis is 1st required (outside mitochondria)
  ___Glucose (6C) is broken down into 2 Pyruvic Acid (3C) molecules
  ___Phosphorylation must 1st occur
  ___Net production: 2 ATP & 2 NADH
  MITOCHONDRIA
  ___Pyruvic Acid & 2NADH enter mitochondria
  ___2 NADH will transfer H (electrons) into ETS
  ___yields 2 x 2 ATP = 4 ATP (some loss due to point of entry into ETS)
  KREBS CYCLE SUBSTRATES
  ___2 Pyruvic Acid loses CO2 & H -> 2 NADH & combines w/CoA -> Acetyl CoA
  ___(2C) Acetyl CoA + (4C) Oxaloacetic Acid -> (6C) Citric Acid
  ___Citric Acid -> Isocitric Acid
  ___(6C) Isocitric Acid - DEHYDROGENATION & loss of CO2 -> (5C) Ketogluatric Acid
                      NAD -> NADH
  ___(5 C) Ketoglutaric Acid - DEHYDROGENATION & loss of CO2 -> (4C) Succinic Acid
                      NAD -> NADH
  ___(4C) Succinic Acid - DEHYDROGENATION -> (4C) Malic Acid
                      FAD -> FADH2
  ___(4C) Malic Acid - DEHYDROGENATION -> Oxaloacetic Acid
                 NAD -> NADH
  ___specific mention of 2 x 3 NADH & 2 x 1 FADH2 produced during Krebs
  ___ATP (1) produced in Krebs
  ETS RECEIVES THE FOLLOWING:  NADH or FADH2 WHICH RESULTS IN ATP PRODUCTION
  ___Glycolysis -> 2 NADH               x 2 ATP =  4
  ___Pyruvic Acid -> Acetyl CoA + 2 NADH     x 3 ATP =  6
  ___Krebs -> 8 NADH (FADH2)            x 3 ATP = 24
                             Total      = 34
  ___34 ATP gained through ETS
  ___Respiratory Assembly: CoQ, cytochromes b, c, a, a3
  ___Ring Compounds w/Fe (porphyrin ring)
  ___Changing Oxidation states as "go down" assembly
  ___Fe III -> Fe II change ionic state as accept electrons
  ___Release energy in "packets" - small amounts sufficient to produce ATP 
     (about 7 kcal/mole)
  ___Occurs at 3 places in the chain for each NADH, FADH2
  ___mention of various hypotheses: Chemiosmotic, Conformational, Chemical Coupling
  ___O2 final acceptor ( -> H2O)