Calvin Cycle

Front

What is the Calvin Cycle?

Back

The Calvin Cycle is a series of biochemical reactions that take place in the stroma of chloroplasts in photosynthetic organisms, where carbon dioxide is converted into glucose using ATP and NADPH produced in the light reactions.

Front

What is the main product of the Calvin Cycle?

Back

Glucose.

Front

What role does RuBP play in the Calvin Cycle?

Back

RuBP (ribulose bisphosphate) is a 5-carbon sugar that combines with carbon dioxide to initiate the Calvin Cycle.

Front

What happens during the carbon fixation stage of the Calvin Cycle?

Back

Carbon dioxide is fixed into an organic molecule by combining with RuBP, catalyzed by the enzyme RuBisCO.

Front

What is the second stage of the Calvin Cycle?

Back

Reduction.

Front

What occurs during the reduction phase of the Calvin Cycle?

Back

In this phase, ATP and NADPH are used to convert 3-PGA (3-phosphoglycerate) into G3P (glyceraldehyde-3-phosphate).

Front

What happens to G3P molecules produced in the Calvin Cycle?

Back

Some G3P molecules are used to regenerate RuBP, while others are used to synthesize glucose and other carbohydrates.

Front

Why can increasing carbon dioxide levels only increase photosynthesis to a maximum rate?

Back

Because the Calvin Cycle can only go as fast as the light reactions, which provide the necessary ATP and NADPH.

Front

How do high temperatures affect the Calvin Cycle?

Back

High temperatures can denature enzymes involved in the Calvin Cycle, slowing down the process.

Front

What is the role of ATP in the Calvin Cycle?

Back

ATP provides the energy required for the conversion of 3-PGA to G3P during the reduction phase.