Refer to the graph below summarizing data collected using rubisco purified from chloroplasts.It shows how the catalytic activity of rubisco changes in response to varying times of incubation, either with an oxidizing agent or with a reducing agent. Thioredoxin is a protein inside the stroma of a chloroplast that can act as an oxidizing or a reducing agent.Thioredoxin is reduced by ferredoxin in photosystem I.Based on this information and the graph, how do you predict thioredoxin will affect rubisco inside cells of a living plant when the plant is moved from the dark into the light?

Question

Refer to the graph below summarizing data collected using rubisco purified from chloroplasts.It shows how the catalytic activity of rubisco changes in response to varying times of incubation, either with an oxidizing agent or with a reducing agent.  Thioredoxin is a protein inside the stroma of a chloroplast that can act as an oxidizing or a reducing agent.Thioredoxin is reduced by ferredoxin in photosystem I.Based on this information and the graph, how do you predict thioredoxin will affect rubisco inside cells of a living plant when the plant is moved from the dark into the light?

Quizplus · Accepted Answer

The graph shows that rubisco activity increases with increasing time of incubation with a reducing agent, which thioredoxin can act as. Therefore, when a plant is moved from the dark into the light and thioredoxin is in a reduced state due to the action of ferredoxin in photosystem I, it is likely that thioredoxin will act as a reducing agent and increase the catalytic activity of rubisco.

Refer to the Graph Below Summarizing Data Collected Using Rubisco