18 Questions
What is the main function of the Calvin Cycle?
Reduction of CO2 to carbohydrate
What is the first stable intermediate of the Calvin Cycle?
3-phosphoglycerate
Which enzyme catalyzes the carboxylation of ribulose-1,5-bisphosphate?
Rubisco
How many stages does the Calvin Cycle proceed through?
Three stages
What is the final stage in the Calvin Cycle?
Regeneration of ribulose-1,5-bisphosphate
What are the products formed during the reduction stage of the Calvin Cycle?
Glyceraldehyde-3-phosphate
What is the negative change in free energy associated with the carboxylation of ribulose-1,5-bisphosphate?
Large
Why is the forward reaction of carboxylation of ribulose-1,5-bisphosphate strongly favored?
The negative change in free energy is large
What is the concentration of rubisco active sites within the chloroplast stroma compared to the concentration of CO2 substrate?
About 500 times greater
What percentage of the total soluble protein in most leaves does rubisco represent?
Up to 40%
How many light-regulated enzymes operate in the Calvin cycle?
Five
What does the kinetic balance between the Calvin cycle and the C2 oxidative photosynthetic carbon cycle depend on?
Rubisco kinetic properties, CO2 and O2 concentrations, and temperature
How does the concentration of CO2 in a solution in equilibrium with air change as the temperature increases?
Decreases more than the concentration of O2
What happens to the balance between photorespiration and photosynthesis as the temperature rises?
Tilted away from the Calvin cycle and toward the oxidative photosynthetic carbon cycle
What effect does increasing temperatures have on the ratio of CO2 to O2 concentrations?
Decreases
What is the theoretical release of CO2 for one-fourth of the carbon entering the C2 oxidative photosynthetic carbon cycle?
One molecule of CO2
What property of rubisco enhances the effect of increasing temperatures on the balance between oxygenation and carboxylation?
Kinetic properties
What is the computed ratio of carboxylation to oxygenation in air at 25°C?
Between 2.5 and 3
Test your knowledge on the Calvin Cycle, the process in photosynthesis where CO2 is reduced to carbohydrates using NADPH and ATP. Learn about the reactions that take place in the stroma of chloroplasts, independent of light.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
