Respiration (aerobic)💨 🫧

• ATP


  An energy source
• Energy is trapped in ATP and released by hydrolysis
• Formation of ATP


  1. Condensation reaction

  2. ADP is added to P to form ATP with the use of ATP synthase
• Input of energy is required, therefore it is an endergonic reaction (30.6kJ/mol)
• Hydrolysis of ATP


  ATP is hydrolysed into ADP and P with the use of ATPase energy is released, therefore its an exergonic reaction (30.6kjmol-3)
• Energy is released, therefore it is an exergonic reaction (-30.6kJ/mol)
• Advantages of ATP vs glucose

  • Only one enzyme is needed to release energy from ATP
  • Releases immediate packets of energy when and where needed
  • Easily transported across membranes
  • Universal energy currency = form of energy used in all biochemical reactions in all living organisms/cells
• Co-enzymes in respiration


  • FADH2
  • NADH
• Oxidation


  Loss of electrons/hydrogen, this is catabolic
• Reduction


  Gain of hydrogen/electron, this is anabolic
• Catabolic


  Breaking down large complex molecules into smaller ones, releasing energy
• Anabolic


  Forming large molecules from smaller ones, using energy
• Glycolysis(in cytoplasm)


  1. Occurs in cytoplasm and O2 is not required

  2. Glucose is phosphorylated by the addition of 2 ATP to form hexose phosphate

  3. Hexose phosphate splits into 2 molecules of triose phosphate

  4. Triose phosphate is dehydrogenated, H+ is removed and transferred to NAD forming reduced NAD and pyruvate

  5. Substrate level phosphorylation occurs forming 2 ATP
• If oxygen is available, pyruvate moves to the link reaction
• Link reaction (in mitochondrial matrix and oxygen is needed)


  1. Pyruvate diffuses into mitochondrial matrix

  2. Pyruvate is dehydrogenated forming reduced NAD

  3. Pyruvate is decarboxylated forming acetate (2C)

  4. Acetate combines with CoenzymA forming acetyl CoA which enters the Krebs cycle
• Krebs cycle (in mitochondrial matrix)


  1. Acetyl CoA combines with 4C compound forming 6 carbon compound, CoA is regenerated back to link reaction

  2. 6C is decarboxylated releasing 1 carbon dioxide and is dehydrogenated reducing NAD

  3. The 5C made is decarboxylated and dehydrogenated releasing one CO2 and reducing 2NAD and 1FAD, ATP is produced through substrate level phosphorylation

  4. The 4C made combines with acetyl coA and the Krebs cycle repeats
• Electron Transport Chain


  1. NADH and FADH deliver their hydrogen atom to the ETC

  2. The hydrogen atom splits into electron and H+

  3. The high energy electron pass through carriers along ETC moving from high energy level to lower energy level

  4. Energy released by electron fuels proton pumps so H+ are pumped from matrix to intermembrane space

  5. Built up of H+ there forms electrochemical gradient

  6. H+ flow down concentration gradient through ion channel Containing ATP synthase (only part permeable to H+), energy released (from flow of H+) used to make ATP from ADP +Pi, this is chemiosmosis

  7. Oxygen acts as final electron acceptor forming H2O
• This whole method is Oxidative phosphorylation
• Glycolysis diagram

  
• respiration equation= C6H12O6+ 6 O2→ 6 CO2+ 6 H2O + 38ATP

  ( Glucose + 6 Oxygen → 6 Carbon Dioxide + 6 Water + ATP )
• ETC diagram

  
• Products of respiration

  
• ATP structure