Limiting Factors in Photosynthesis and Their Impact on the Calvin Cycle

The video explains limiting factors in photosynthesis, focusing on light intensity, carbon dioxide concentration, and temperature. It describes how these factors affect the light-dependent and light-independent reactions, particularly in the Calvin Cycle. The video also discusses the role of water and how it indirectly becomes a limiting factor when plants close their stomata to conserve water, affecting carbon dioxide intake.

What are the products of the light-dependent reactions in photosynthesis?

• Triose phosphate and glycerate 3-phosphate

• Carbon dioxide and water

• ATP and reduced NADP

• Glucose and oxygen

How does increasing light intensity initially affect the rate of photosynthesis?

• It stops the process

• It decreases the rate

• It has no effect

• It increases the rate

What happens when light intensity is no longer the limiting factor in photosynthesis?

• The plant dies

• The rate of photosynthesis decreases

• Another factor becomes limiting

• Photosynthesis stops

Which factor can become limiting when light intensity is high?

• Chlorophyll

• Carbon dioxide

• Oxygen

• Water

What role does rubisco play in the Calvin cycle?

• It transports electrons

• It absorbs light energy

• It catalyzes the fixation of carbon dioxide

• It splits water molecules

How does low temperature affect rubisco's activity?

• It decreases rubisco's activity

• It has no effect

• It stops rubisco completely

• It increases rubisco's activity

Why is water not usually considered a limiting factor in photosynthesis?

• Because it is not required for photosynthesis

• Because plants can store unlimited water

• Because its scarcity leads to stomatal closure, affecting carbon dioxide

• Because it is always abundant

What happens to carbon dioxide concentration when water is scarce?

• It decreases

• It remains constant

• It becomes irrelevant

• It increases

What happens to glycerate 3-phosphate when light intensity is low?

• It becomes triose phosphate

• It converts to glucose

• Its concentration increases

• Its concentration decreases

What is the effect of low carbon dioxide concentration on ribulose bisphosphate?

• Its concentration decreases

• Its concentration increases

• It converts to glucose

• It becomes triose phosphate