Question

Algae are single-celled photosynthetic organisms. An investigation was carried out into the effect of CO2 concentration on the concentrations of ribulose diphosphate (RuBP) and glycerine 3-phosphate (GP) present in algae. Algae were grown in a solution containing a high concentration of CO2. The concentration of CO2 was then reduced. RuBP and GP concentration were measured for 2 minutes before and 3 minutes after the reduction in CO2 concentration.

Describe and explain the effect of reducing the CO2 concentration of RuBP and GP in the algae.

Answer 1

If carbon dioxide is reduced, then less GP is produced. The lack of carbon dioxide means that there is less substrate for RuBP to react with. As a result, the amount or activity of RuBP will increase to fix carbon dioxide fore efficiently.