Why does Rubisco show relatively little preference for CO₂ as a substrate over O₂? A)Rubisco's active site can bind to CO₂ and O₂ equally well. B)CO₂ and O₂ bind to RuBP which has roughly equal affinity for CO₂ and O₂. C)Ancient atmospheric conditions had high amounts of O₂ which selected for Rubisco to bind to either molecule. D)CO₂ and O₂ bind to a regulatory site on Rubisco instead of the active site.

Question

Quizplus · Accepted Answer

Rubisco's substrate, RuBP, has roughly equal affinity for CO₂ and O₂, meaning that the preference for either substrate is not significant. Additionally, Rubisco's active site is known to have difficulty distinguishing between structurally similar molecules. Therefore, the lack of preference for either substrate is likely due to the structural similarity between CO₂ and O₂ and the equal affinity of RuBP for both substrates.

Why Does Rubisco Show Relatively Little Preference for CO2 as a Substrate

Why Does Rubisco Show Relatively Little Preference for CO₂ as a Substrate