aerobic respiration

• Four stages of respiration

  1. glycolysis
  2. link reaction
  3. Krebs cycle
  4. oxidative phosphorylation
• Glycolysis products per glucose

  2 ATP

  2 NADH

  2 pyruvate
• Glycolysis steps


  1. phosphorylation - to form hexose biphosphate, hydrolysis to form two triose phosphate molecules
  2. oxidation - involved NAD and ADP to form two pyruvate molecules
• Glycolysis

  • anaerobic process
  • occurs in the cytoplasm
• Link reaction

  • aerobic process
  • occurs in the matrix
  • PYRUVATE DEHYDROGENASE - catalyst involved
• Link reaction products per pyruvate

  • 1 carbon dioxide
  • 1 NADH
  • 1 acetyl CoA
• Link reaction


  1. dehydrogenation and decarboxylation to form acetate (2C)
  2. addition of coenzyme A to form acetyl CoA (2c)
• Krebs cycle


  • aerobic process
  • occurs in the matrix
  • a series of oxidation-reduction reactions
• Intermediates of the Krebs cycle

  1. oxaloacetate (4C)
  2. citrate (6C)
  3. 5-carbon intermediate (5C)
  4. oxaloacetate (4C)
• Krebs cycle products per acetyl CoA

  • 3 NADH
  • 1 FADH2
  • 2 CO2
  • 1 ATP

  multiply by 2 for per glucose
• Krebs cycle

  A) citrate

  B) oxaloacetate

  C) ATP

  D) NADH

  E) FADH2

  F) NADH

  G) CO2

  H) CO2

  I) NADH

  
• Krebs cycle purpose


  • NAD and FAD are coenzymes as they transport H+ ions for oxidative phosphorylation
  • CO2 is produced as an end product in this step
  • some ATP is produced in this process
• Oxidative phosphorylation


  • occurs in the inner mitochondrial membrane
  • proteins involved are embedded within this membrane
  • generates large amounts of ATP
• Oxidative phosphorylation

  1. electron transport chain
  2. ATP synthase
  3. electron acceptance
• oxidative phosphorylation - ETC

  • NADH, later FADH2 releases H+ and e-
  • electrons pass along ETC provides energy to pump H+ INTO the INTER-MEMBRANE SPACE
  • HIGH CONC OF H+ in the inter membrane space
  • LOW CONC OF H+ in the matrix
• oxidative phosphorylation- ATP synthase

  • facilitated diffusion through proton channel of ATP synthase
  • proteins flow from inter membrane space to the matrix
  • ATP synthase spins!
  • ADP + Pi -> ATP
  • process is called CHEMIOSMOSIS
• Oxidative phosphorylation - electron acceptance

  • oxygen in the final acceptor of electrons from the ETC
  • 2H+ + 2e- + 1/2 O2 -> H2O
• Oxidative phosphorylation


  • REMEMBER: H+ provided by coenzymes - NADH and FADH2
  • 1 NADH accounts for 2.5 ATP
  • 1 FADH2 accounts for 1.5 ATP
• OVERALL ATP PRODUCED per glucose: 32

  • 2 ATP from glycolysis
  • 2 ATP from Krebs cycle (2 cycles per glucose)
  • 10 NADH in oxidative phosphorylation -> 25 ATP
  • 2 FADH in oxidative phosphorylation -> 3 ATP
• OVERALL NADH by oxidative phosphorylation per glucose

  • 2 from glycolysis
  • 2 from the link reaction
  • 6 from the Krebs cycle