Aerobic respiration

• Cellular respiration


  The process by which cells convert the chemical energy in glucose and other organic molecules into a form that can be used by the cell, ATP

  
• Photosynthesis


  The process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar

  
• Cellular respiration and photosynthesis

  Complementary processes, the products of one are the reactants of the other

  
• Cellular respiration


  Equation: Glucose is oxidized to produce ATP, mainly occurs in the mitochondria, carried out by plants and animals

  
• Glucose


  Has too much energy for cellular processes, cellular respiration breaks it down into small packets of energy in the form of ATP

  
• ATP


  The source of energy for most cellular processes such as active transport, muscle contraction, nerve impulse, synthesizing compounds, cell division, growth and repair
• Stages of aerobic cellular respiration

  1. Glycolysis

  2. Pyruvate oxidation (transition reaction)

  3. Krebs cycle

  4. Electron transport chain (oxidative phosphorylation)

  
• Mitochondria


  • Inner membrane, outer membrane, cristae, matrix, intermembrane space
• Glycolysis


  Glucose (6 carbons) breaks down to form two pyruvate molecules (3 carbons each), occurs in the cytoplasm, does not require oxygen (anaerobic)

  
• Pyruvate


  Also called pyruvic acid
• Glycolysis requirements


  Glucose, 2 NAD+ (reduced to 2 NADH), 2 ADP (phosphorylated to 2 ATP)

  
• Glycolysis products


  2 pyruvate molecules, 2 ATP, 2 NADH

  
• Pyruvate oxidation


  Pyruvate (3 carbons) is oxidized to form acetyl CoA (2 carbons), carbon dioxide is removed (decarboxylation), acetyl CoA carries the 2 carbons to the Krebs Cycle

  
• Pyruvate oxidation requirements


  2 molecules of pyruvate, 2 molecules of coenzyme A, 2 NAD+ (reduced to 2 NADH)

  
• Pyruvate oxidation products


  2 molecules of acetyl CoA, 2 molecules of CO2, 2 molecules of NADH

  
• Krebs cycle


  Occurs in the matrix of the mitochondria, coenzyme A drops off 2 carbons and is recycled, the 2 carbons react with a 4-carbon "starter" molecule to form a 6-carbon molecule (citric acid)

  
• Krebs cycle requirements


  2 molecules of acetyl CoA (from pyruvate oxidation), 6 NAD+ (reduced to 6 NADH), 2 FAD (reduced to 2 FADH2), 2 ADP (phosphorylated to 2 ATP)

  
• Krebs cycle products


  2 molecules of CoA (reused for pyruvate oxidation), 4 molecules of CO2, 2 molecules of FADH2, 6 molecules of NADH, 2 molecules of ATP

  
• Electron transport chain


  Occurs in the intermembrane space or on the cristae, NADH and FADH2 drop off their high energy electrons and they are passed down an electron transport chain
• Electron transport chain - two step movement of H+


  Step 1: Energy lost by electrons used to pump hydrogen ions from matrix into intermembrane space

  Step 2: Hydrogen ions in intermembrane space diffuse back into matrix through ATP synthase, resulting in ATP production through chemiosmosis

  
• Oxygen


  The final electron acceptor in the electron transport chain, reduced to water
• Oxidative phosphorylation


  The formation of ATP using oxygen
• Products from 1 molecule of glucose

  Glycolysis: 2 NADH, 2 ATP

  Pyruvate Oxidation: 2 NADH, 2 CO2

  Krebs Cycle: 4 CO2, 6 NADH, 2 FADH2, 2 ATP

  Electron Transport Chain and Oxidative Phosphorylation: 32 ATP

  Total: 36 ATP