Question

the affinity of rubisco for CO₂ over O₂ decreases at higher temperatures. what effect if any would this have on the amount of photorespiration, the efficiency of photosynthesis and why? as average global temperatures rise what effect could it potentially have on crop yields

Answer 1

The increase in temperature reduces the affinity of rubisco for CO₂ over O₂, leading to increased photorespiration and reduced efficiency of photosynthesis. This can potentially decrease crop yields as average global temperatures rise.

Step-by-step explanation:

The affinity of rubisco for CO₂ over O₂ decreases at higher temperatures. This temperature effect on Rubisco has several implications:

1. Photorespiration: At higher temperatures, with a lower affinity for CO₂, rubisco is more likely to react with oxygen. This leads to increased photorespiration, which is the process by which Rubisco uses oxygen instead of carbon dioxide, resulting in the production of a 2-carbon molecule and reduced efficiency of photosynthesis.
2. The efficiency of Photosynthesis: The decreased affinity of rubisco for CO₂ at higher temperatures reduces the efficiency of photosynthesis. With less efficient carbon fixation, the overall rate of photosynthesis decreases.
3. Effect on Crop Yields: As average global temperatures rise, the increased temperature can lead to reduced crop yields due to the negative effects of higher temperatures on photosynthesis and increased photorespiration. This can result in decreased productivity and lower crop yields.