Bio photo exam

• What are the light dependent reactions in photosynthesis responsible for producing?

  ATP and reduced NADP
• Where do the light dependent reactions take place?

  On the thylakoid membranes
• What is produced as a byproduct of the light dependent reactions?

  Oxygen
• What are the two types of photo phosphorylation involved in the light dependent reactions?

  Non-cyclic and cyclic photo phosphorylation
• What is the role of photosystems in the light dependent reactions?

  They absorb light energy
• Which photosystems are involved in the light dependent reactions?

  Photosystem II (PS2) and Photosystem I (PS1)
• What happens to the electrons after they are excited in Photosystem II?

  They pass through an electron transport chain
• How is ATP produced during the light dependent reactions?

  Through chemiosmosis
• What is the process called when water is split to replace lost electrons in Photosystem II?

  Photolysis
• What is the source of oxygen produced in photosynthesis?

  From the photolysis of water
• What distinguishes non-cyclic photo phosphorylation from cyclic photo phosphorylation?

  In non-cyclic, electrons do not return to PS2, while in cyclic, they return to PS1
• When does cyclic photo phosphorylation occur?

  When the chloroplast requires an increased amount of ATP
• What is the role of the electron transport chains in the light dependent reactions?

  They use the energy of electrons to pump protons into the thylakoid interior
• What is created as a result of the proton gradient established during the light dependent reactions?

  ATP
• What enzyme is responsible for generating ATP in the light dependent reactions?

  ATP synthase
• How do protons move through ATP synthase to generate ATP?

  They diffuse down the proton gradient
• What are the key processes involved in the light dependent reactions of photosynthesis?

  • Light absorption by photosystems
  • Excitation of electrons
  • Electron transport chains
  • Production of ATP via chemiosmosis
  • Photolysis of water
  • Formation of reduced NADP
• What are the differences between non-cyclic and cyclic photo phosphorylation?

  Non-cyclic photo phosphorylation:

  • Electrons do not return to PS2
  • Produces ATP and NADPH
  • Involves both PS2 and PS1

  
  

  Cyclic photo phosphorylation:

  • Electrons return to PS1
  • Produces only ATP
  • Involves only PS1
• What is the main purpose of the light dependent reactions in photosynthesis?

  To convert light energy into chemical energy in the form of ATP and NADPH
• What is the significance of the proton gradient in the light dependent reactions?

  It drives the synthesis of ATP through chemiosmosis
• What are the light independent reactions in photosynthesis also called?

  Calvin cycle
• Where do the light dependent reactions take place?

  On the thylakoid membranes
• What is produced during the light dependent reactions?

  ATP and reduced NADP
• What is split during the light dependent reactions?

  Water
• Where do the light independent reactions take place?

  In the stroma
• What do the light independent reactions use from the light dependent reactions?

  ATP and reduced NADP
• What is the main product of the light independent reactions?

  Glucose
• Do the light independent reactions require light?

  No
• What are the stages of the Calvin cycle?

  1. Fixation: Ribulose bisphosphate reacts with carbon dioxide.
  2. Reduction: Glycerate 3 phosphate is reduced to triose phosphate.
  3. Regeneration: Ribulose bisphosphate is regenerated using ATP.
• What is the five carbon molecule that reacts with carbon dioxide in the Calvin cycle?

  Ribulose bisphosphate (RuBP)
• What enzyme catalyzes the reaction of ribulose bisphosphate with carbon dioxide?

  Ribulose bisphosphate carboxylase (rubisco)
• How many molecules of glycerate 3 phosphate are produced from one reaction of ribulose bisphosphate with carbon dioxide?

  Two molecules
• How many carbon atoms does each molecule of glycerate 3 phosphate have?

  Three carbon atoms
• What is formed from glycerate 3 phosphate during the reduction stage?

  Triose phosphate (TP)
• What do reduced NADP and ATP provide during the reduction stage?

  Hydrogen and energy
• What happens to some of the triose phosphate produced in the Calvin cycle?

  It is used to make glucose and other molecules
• What is regenerated during the final stage of the Calvin cycle?

  Ribulose bisphosphate (RuBP)
• How many times does the Calvin cycle need to turn to produce one molecule of glucose?

  Six times
• How do the light dependent and light independent reactions link together in photosynthesis?

  • Light dependent reactions produce ATP and reduced NADP.
  • Light independent reactions use ATP and reduced NADP to convert carbon dioxide into glucose.
• What will the next video discuss after the light independent reactions?

  How limiting factors can affect the rate of photosynthesis