LDR photosynthesis

• What is the first stage of photosynthesis?

  Light dependent reactions
• How many stages are there in photosynthesis?

  Two stages
• Where do the light dependent reactions occur?

  In the thylakoid membranes
• What are the thylakoid membranes also referred to as?

  Grana (plural) or Granum (singular)
• What is required for the light dependent reactions to occur?

  Light energy
• What do the light dependent reactions produce?

  ATP and reduced NADP
• What are the four key reactions in the light dependent reactions?

  Photoionization, photolysis, ATP production, chemiosmosis
• What does photolysis of water mean?

  Light energy splits water
• What are the products of photolysis of water?

  Oxygen, electrons, and protons
• What happens to protons during photolysis?

  They are picked up by NADP
• What is the role of electrons in the light dependent reactions?

  They release energy along a chain
• What is photoionization?

  Loss of electrons from chlorophyll
• What happens to chlorophyll during photoionization?

  It loses an electron
• What is chemiosmosis?

  Process of ATP production using a gradient
• How is ATP produced in the light dependent reactions?

  Through the action of ATP synthase
• What creates the electrochemical gradient in the thylakoid lumen?

  Protons being pumped across the membrane
• What is the function of ATP synthase?

  To catalyze ATP production
• What happens to protons after they pass through ATP synthase?

  They return to the stroma
• What does reduced NADP mean?

  NADP that has gained protons and electrons
• What is the overall purpose of the light dependent reactions?

  To produce ATP and reduced NADP for the next stage
• What are the main steps involved in the light dependent reactions?

  1. Light absorption by chlorophyll
  2. Photolysis of water

  • Produces oxygen, electrons, and protons

  1. Photoionization of chlorophyll

  • Electrons are lost

  1. Electron transfer chain

  • Electrons release energy

  1. Chemiosmosis

  • ATP production via ATP synthase
  • Reduced NADP formation
• What are the key differences between the light dependent and light independent reactions?

  • Light dependent reactions:
  • Require light
  • Produce ATP and NADPH
  • Occur in thylakoid membranes
  • Light independent reactions:
  • Do not require light
  • Use ATP and NADPH to synthesize glucose
  • Occur in the stroma