Photosynthesis

Light Reactions: Photosystem II Light strikes photsystem II The light also causes a water molecule to split. An electron from the water moves into the E transport system, moving through the membrane electron carriers the H+ moves into the thylakoid space (inside the membrane) O2 is released as a waste product. http://www.science.smith.edu/departments/Biology/Bio231/ltrxn.html

Electron Transport Chain The electron acceptor molecules transfer the electrons through the membrane Protons (H+) are pumped into the thylakoid space by the from the stroma.

The Light reactions

Photosystem I The electrons reach Photosystem I and are re-energized forming the energy storage molecule (intermediate) NADPH (later to be turned into ATP)

Chemiosmosis Protons accumulate in the thylakoid space during Photosystem II (breakdown of water and pumping in of protons). Creates a concentration gradient. Protons move through the ATP Synthase channels (enzymes) and form ATP in the stroma of the chloroplast.

Overall Light Reaction Photosystem II: In: Water and Light Out: electons to chain, protons in thylakoid, O2 out Photosystem I: -In: Electrons from Photosystem I and NADP in carriers -Out: NADPH for dark reaction and ATP in stroma

Dark Reaction: Calvin Cycle A series of reaction that use carbon dioxide to produce glucose NADPH provides Hydrogen for the cycle ATP provides energy for the cycle Glucose is produced!