5.6.2 Light-independent reactions

• NADPH provides reducing power by donating electrons during the reduction phase of the Calvin cycle.


  True
• ATP and NADPH are essential components of the Calvin cycle, with ATP acting as an energy source and NADPH as a reducing agent.
• What is another name for the light-independent reactions?

  Calvin cycle
• The light-independent reactions require carbon dioxide and energy-rich molecules ATP and NADPH.

  True
• Which enzyme catalyzes the reaction between CO2 and RuBP in the Calvin cycle?

  Rubisco
• Match the molecule with its role in the Calvin cycle:

  Carbon dioxide ↔️ Primary carbon source for fixation

  ATP ↔️ Energy source for reduction

  NADPH ↔️ Reducing power for 3-PGA

  Rubisco ↔️ Enzyme catalyzing CO2 fixation
• Rubisco is the enzyme responsible for catalyzing the reaction between CO2 and RuBP.


  True
• RuBP serves as the substrate for carbon fixation
• The substrate for carbon fixation in the Calvin cycle is RuBP
• Steps involved in the activation of carbon dioxide in the Calvin cycle

  1️⃣ CO2 combines with RuBP

  2️⃣ Rubisco catalyzes the reaction

  3️⃣ A six-carbon intermediate is formed

  4️⃣ The intermediate breaks down into 3-PGA
• RuBP binds to CO2 to form a six-carbon intermediate
• What is 3-PGA converted to in the Calvin cycle?

  Glucose
• 3-PGA serves as the substrate for the reduction phase of the Calvin cycle.
• What type of molecule is G3P?

  Three-carbon sugar
• Which enzyme catalyzes the reduction of 1,3-bisphosphoglycerate in the Calvin cycle?

  GAPDH
• What enzyme facilitates the fixation of carbon dioxide in the Calvin cycle?

  Rubisco
• RuBP is regenerated from G3P using ATP in the Calvin cycle.


  True
• Rubisco catalyzes the reaction between CO2 and RuBP in carbon fixation.


  True
• Which molecule is combined with CO2 during carbon fixation in the Calvin cycle?

  RuBP
• ATP provides the energy needed for both reduction and regeneration phases in the Calvin cycle.


  True
• The enzyme responsible for catalyzing the reaction between CO2 and RuBP is rubisco
• What is the three-carbon sugar produced after the reduction phase in the Calvin cycle?

  G3P
• Rubisco catalyzes the reaction between CO2 and RuBP in the input of carbon dioxide step.


  True
• RuBP binds to CO2 to form a six-carbon intermediate.

  True
• What is the first step in the Calvin cycle called?

  Activation of carbon dioxide
• The reduction of 1,3-bisphosphoglycerate to G3P requires the enzyme GAPDH
• The enzyme that catalyzes the incorporation of CO2 into organic compounds is called rubisco
• The phosphorylation of 3-PGA by PGA kinase requires one ATP molecule per 3-PGA molecule.


  True
• The light-independent reactions occur in the stroma
• Steps in the light-independent reactions

  1️⃣ Carbon dioxide is fixed and converted into 3-carbon sugar molecules

  2️⃣ 3-carbon compounds are rearranged and combined to form glucose

  3️⃣ Glucose is used for energy or other organic compounds
• 3-PGA is an intermediate product in the Calvin cycle that is converted to glucose using ATP
• What does RuBP combine with during carbon fixation in the Calvin cycle?

  CO2
• What is the primary carbon source for the Calvin cycle?

  Carbon dioxide
• What is the primary carbon source in the Calvin cycle?

  CO2
• Rubisco catalyzes the reaction between CO2 and RuBP in the Calvin cycle.

  True
• What is the role of CO2 in the Calvin cycle?

  Primary carbon source
• Rubisco is essential for carbon fixation in the Calvin cycle.


  True
• Match the molecule/enzyme with its role in the Calvin cycle:

  3-PGA ↔️ Starting molecule for reduction

  ATP ↔️ Energy source for phosphorylation

  NADPH ↔️ Reducing power for 1,3-bisphosphoglycerate

  G3P ↔️ Three-carbon sugar product
• NADPH provides the reducing power needed to convert 1,3-bisphosphoglycerate to G3P.

  True
• PGA kinase catalyzes the phosphorylation of 3-PGA using ATP.


  True