Chap. 7 : Cellular Respiration

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Chap. 7 Cellular Respiration

• -- the making of ATP by breaking down
  organic compounds (mostly glucose)
• Glycolysis
• -- glucose splits into 2 pyruvic acids
• -- occurs in the cytoplasm
• -- requires 2 ATPs but produces 4 so net
  gain of 2 ATPs
• -- also produces 2 NADH (high
  energy)molecules

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• The end result is 2 pyruvates, 2 H2O,2NADH, and 2
  ATP

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II. Fermentation occurs in the absence of
oxygen (anaerobic). Done in cytoplasm

• 1. Lactic Acid Fermentation
• -- changing of pyruvic acid from
  glycolysis into lactic acid
• -- does not produce ATP so no energy but
  produces NAD that is used to continue glycolysis
  
• We can intentionally use to make
  things like yogurt, cheese, sauerkraut
• Lactic acid builds up in muscles
  causing them to cramp,fatigue, and pain

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2. Alcoholic Fermentation converts pyruvic acid
into ethyl alcohol (ethanol)

• Accomplished by yeast used to make beer and
  wine and if CO2 stays trapped then champagne.
• In bread making the escaping of CO2 makes air
  bubbles, the alcohol evaporates while baking
• Anaerobic respiration only produces enough
  energy for unicellular or small multicellular
  organisms to survive.

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III. Aerobic Respiration occurs when O2 is
available for pyruvic acid after glycolysis

• Occurs in cytoplasm in prokaryotes and in
  mitochondria of eukaryotes.
• 3 parts
• 1.changing pyruvic acid into Acetyl CoA
  with the use of CoA enzyme. Makes 2 NADH
• 2. Krebs Cycle-p.138

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The end result of Krebs Cycle 1 glucose
molecule makes

• 6 NADH, 2 FADH2, 2 ATP, and 4 CO2 (everything
  doubled because it started with 2 pyruvic acids
  from glucose so goes through Krebs Cycle twice)
• 3. Electron Transport Chain (chemiosmosis) or
  oxidative phosphorylation-changing ADP into ATP
  by reducing NADH to NAD and FADH2 to FAD
• IV. Electron Transport Chain (ETC)
• most important step for making energy
  (ATP) for cell.
• --- occurs in cristae of mitochondria. ATP
  synthase molecules line membrane. Chemiosmosis
  (changing ADP into ATP) occurs here by proton
  concentration differences.

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A. Overall Energy Output from Respiration

• 1 NADH 3ATP
• 1 FADH2 2 ATP
• Glycolysis 2 ATP 2NADH
• 8 ATP total
• making Acetyl CoA 2 NADH
• 6 ATP
• Krebs Cycle 6 NADH, 2 FADH2, 2ATP
• 18 4 2 24
• Total ATP from the splitting of one glucose
  molecule 38 ATP