Photosynthesis - light dependent

• The light dependent stage is the first set of reactions.
• Where do the reactions occur in the light dependent stage?

  Occur in the thylakoid membranes inside of chloroplasts.
• Photosystem 1 (PSI) = found on the intergranal lamellae
• Photosystem 2 (PSII) = found almost exclusively on the granal lamelae
• What is the focus of the light dependent stage?

  Converting light energy trapped by pigments in photosynthesis into chemical energy.
• What happens in PSII?

  PSII has an enzyme which in the presence of light, splits into a molecule of water into protons, electrons and oxygen.
• Oxygen = waste product
• The oxygen produced is the source of almost all oxygen in the atmosphere, many organisms use it to respire and therefore live.
• Plants us some oxygen to aerobically respire but most leaves via the stomata.
• Protons are used to generate ATP molecules by chemiosmosis.