High temperatures increase reaction rates but lower rubisco selectivity for CO₂ versus O₂. High leaf temperatures thus: A)increase photorespiration rates. B)decrease photorespiration rates. C)increase respiration. D)decrease RuBP carboxylation. E)increase RuBP carboxylation.

Question

Quizplus · Accepted Answer

High temperatures increase the activity of Rubisco enzyme, but also increase the oxygenase activity of the enzyme, leading to the breakdown of RuBP and the release of CO₂ and ammonia in a process called photorespiration. Therefore, high temperatures increase photorespiration rates.

High Temperatures Increase Reaction Rates but Lower Rubisco Selectivity for CO2

High Temperatures Increase Reaction Rates but Lower Rubisco Selectivity for CO₂