Respiration

• Aerobic respiration formula: 6C6 H12 O6 + 6O2  —-> 6CO2 + 6H2O + ATP
• Glycolysis takes place in cytoplasm
• Glycolysis: Glucose is first phosphorylated to produce glucose 1, 6-phosphate

  This requires 2 x ATP molecules that are converted to ADP

  Glucose 6-phosphate to then split to produce 2 x Triose phosphate . Triose phosphate is then oxidised into Pyruvate
• In glycolysis X2 ATP molecules are produced from each triose phosphate conversion and X1 NADH is produced from each conversion
• Link reaction takes place in mitochondrial matrix
• Link reaction: Pyruvate (3C) is oxidised to Acetate (2C). This produces NADH and CO2

  (decarboxylation). Acetate combines with Coenzyme A and is converted to

  Acetlycoenzyme A (2C)

  This reduces 1 x NAD molecule to NADH.

  This also release 1 x CO2 molecule
• The krebs cycle takes place in the mitochondrial matrix
• Krebs cycle:

  1. Acetylcoenzyme A (2C) combines with a 4C molecule to produce a 6C

  molecule.

  2. The 6C molecule is then converted back to the original 4C molecule. This

  results in the following:

  The release of 2 x CO2 molecules

  The reduction of 3 x NAD molecules to NADH

  The reduction of 1 x FAD molecules to FADH

  The generation of 1 x ATP molecule by SUBSTRATE LEVEL

  PHOSPHORYLATION
• Oxidative phosphorylation happens in the inner mitochondrial membrane
• What is the first step in oxidative phosphorylation?

  NADH passes an electron to a first electron carrier.
• How is energy utilized during the transfer of electrons in oxidative phosphorylation?

  The energy from the electron transfer is used to transport H+ across the inner-mitochondrial membrane.
• What happens to H+ ions during the first electron transfer in oxidative phosphorylation?

  H+ is transported from the matrix into the inter-membrane space.
• What occurs after the first electron carrier in oxidative phosphorylation?

  The first electron carrier passes the electron to a second electron carrier.
• What is the role of the second electron carrier in oxidative phosphorylation?

  The second electron carrier passes the electron to a third electron carrier.
• How does the energy from the second electron transfer affect H+ ions?

  The energy from this transfer is used to transport H+ across the inner-mitochondrial membrane.
• What is the effect of the electron transfer on H+ ions during the process?

  The energy from the transfer is used to transport H+ across the inner-mitochondrial membrane.
• What happens to heat during the movement of H+ across the inner mitochondrial membrane?

  Heat is lost as each H+ moves across the inner mitochondrial membrane.
• What type of reactions occur during the movement of electrons in oxidative phosphorylation?

  The movement of the electron occurs through a series of Redox reactions.
• What is the final electron acceptor in oxidative phosphorylation?

  The final electron acceptor is O2.
• What is produced when O2 acts as the final electron acceptor in oxidative phosphorylation?

  O2 is converted to H2O together with H+ present in the mitochondrion.
• What are the main steps involved in oxidative phosphorylation?

  1. NADH passes an electron to the first electron carrier.
  2. H+ is transported across the inner-mitochondrial membrane.
  3. The first electron carrier passes the electron to the second carrier.
  4. H+ is transported again across the membrane.
  5. The second electron carrier passes the electron to the third carrier.
  6. H+ is transported once more across the membrane.
  7. Heat is lost during H+ movement.
  8. Electrons move through Redox reactions.
  9. O2 is the final electron acceptor, forming H2O.
• Chemiosmosis is the last stage of aerobic respiration: The H+ flood through ATP synthase from the inter-membrane space back into the

  matrix. As they do ADP + Pi is converted to ATP.
• In anaerobic respiration glycolysis is the only stage that can still occur as pyruvate becomes the final electron acceptor, oxidising NADH