respiration

• 5.1 PHOTOSYNTHESIS

  • Occurs in chloroplasts
  • Chloroplasts are organelles with a double phospholipid bilayer membrane envelope
  • They are fluid filled sacks-this is called the stroma where the LIGHT INDEPENDENT STAGE occurs
  • In the stroma are stacks of fluid filled sacks called thylakoids which stack on top of each other to form grana connected by lamellae
  • The thylakoids are where the LIGHT DEPENDANT STAGE occurs
  • Chloroplasts are also full of ribosomes, starch grains, a loop of dna and structures called photosystems
  • There are 2 photosystems which are complexes of proteins attached to photosynthetic pigments
  • There are three pigments- carotenoids, chlorophyll a and chlorophyll b
  • The pigments absorb different wavelengths of light
• 5.2 RESPIRATION


  • Two types- aerobic and anaerobic
  • Both produce ATP- aerobic more so
  • Both begin with glycolysis
  • In aerobic first there is glycolysis, then the link reaction then the Krebbs cycle then oxidative phosphorylation
  • Glycolysis has two stages- phosphorylation and oxidation
  • Glycolysis provides pyruvate
  • In aerobic respiration its then used in the link reaction
  • In anaerobic respiration, pyruvate is converted to lactate (mammals) or ethanol (things like yeast)
  • 32 ATP can be made from one glucose!
• ATP production


  1. Phosphorylation of ADP

  2. Intermediate processes (not on spec)
• Citrate conversion


  1. Citrate converted to oxaloacetate

  2. Citrate 6C converted to 5C

  3. CO2 removed (decarboxylation)

  4. Hydrogen removed (dehydrogenation)

  5. Hydrogen used to reduce NAD
• 2 CO2, 1 ATP, 1 reduced FAD, 3 reduced NAD produced
• Oxidative phosphorylation


  • Uses 1 reduced FAD and 3 reduced NAD from Krebs cycle
  • Makes lots of ATP
  • Involves electron transport chain and chemiosmosis
• Oxidation of reduced FAD and NAD

  1. FAD and NAD lose hydrogen

  2. Hydrogen splits into H+ and protons and electrons

  3. Electrons move down ETC and lose energy

  4. Energy used to pump protons into intermembrane space

  5. Protons move back into matrix via ATP synthase to phosphorylate ADP to ATP

  6. Protons and electrons combine with oxygen to form water
• Chemiosmotic theory


  • ATP production driven by protons moving across a membrane due to electron movement
• Oxygen is the final electron acceptor
• Photosynthetic pigments, such as chlorophyll, absorb different wavelengths of visible light.
• The stroma contains enzymes that catalyse reactions involved in carbon fixation.
• Chloroplasts contain thylakoids which are stacked together to make grana.