PHOTOSYNTHESIS 2

Main products of the Calvin Cycle

• Oxygen, NADP+, ADP

• Glucose, CO2, ADP

• ADP, NADP+, Glucose

• ATP, NADPH, Oxygen

What happens to the remaining G3P molecules in the last step of the dark reactions?

• They are used to make glucose.
• They are reshuffled to make CO₂ by adding ATP.
• They exit the cycle.
• They are reshuffled to make RuBP by adding ATP. 

How many G3P molecules make one molecule of glucose? 

• 1
• 2
• 3
• 4

How many carbons does G3P have?

• 1
• 2
• 3
• 6

How many carbon atoms are in RuBP?

• 2
• 3
• 4
• 5

CAM and C4 Plants each prevent Photorespiration by...

• Storing CO₂ in a form that can be used during times their stomata are closed.

• Keeping their stomata open at all times to prevent low CO₂ levels.

• A special carrier protein that prevents the entrance of Oxygen into leaves.

• Altering (alosteric inhibition) the enzyme RUBISCO to prevent photorespiration.

Why photorespiration occurs when the concentration of O₂ is higher than the concentration CO₂?

• Rubisco has higher affinity to O₂

• Rubisco has higher affinity to CO₂

• CO₂ act as competitive inhibitor

• CO₂ can bind to Rubisco

What is the similarity between CAM pathway and C₃ pathway?

• Both occur in mesophyll cells

• Both occur in bundle sheath cells

• Both occur in during day time

• Both occur in during night time

Why photorespiration is wasteful?

• Phosphoglycolate breakdown into CO₂ without producing organic molecule.

• Phosphoglycolate is a high energy molecule

• Photorespiration increase the production of Glyceraldehyde-3-phosphate by 40%

Why malate is stored in vacuole in CAM plant?

• To be decarboxylated during the day

• To prevent decrease in pH in cytoplasm

• To be decarboxylated during night

• To be transported to bundle sheath cell