ATP Synthesis

• ATP Synthesis via Chemiosmosis
• ATP synthesis

  • results from LDR (both linear and cyclic e- flow)
• How do we get ATP?

  1. Energy from ETC is used to pump H+ from the stroma to the thylakoid lumen
  2. Now created a proton gradient (H+) over thylakoid membran
• ATP Synthase

  • transmembrane protein
  • forms a channel
  • H+ can now move through channel (the proton gradient means one side of membrane has more protons than other, we want to get it back to normal)
  • this creates energy used for photophosphorylation (ADP+Pi to ATP)
• Chloroplast vs. Mitochondria Similarities

  • double-membranes
  • involve and create H+ gradients
  • driven by ATP synthase
• Chloro. vs mito. Differences

  • source of e-
  • in mitochondria the e- comes from organic molecule (glucose)
  • Chloroplasts get e- overall from water (H2O)
  • this allows light E to turn into chemical E of ATP