C4 plants are more efficient because a the enzyme they use t

C4 plants are more efficient because: a) the enzyme they use to fix Co2 to RUBP is not attrcated to O2 b) they carry out the light reactions and the calvin cycle in seperate cells c) they have guard cells that keep oxygen molecules out of their leaves d) they have guard cells that keep carbon dioxide molecules out of their leaves

Solution

Answer:

a) the enzyme they use to fix Co2 to RUBP is not attrcated to O2

Explanation:

C4 plants chemically fix carbon dioxide in the cells of the mesophyll by adding it to the three-carbon molecule phosphoenolpyruvate (PEP), a reaction catalyzed by an enzyme called PEP carboxylase, creating the four-carbon organic acid oxaloacetic acid. Oxaloacetic acid or malate synthesized by this process is then translocated to specialized bundle sheath cells where the enzyme RuBisCO and other Calvin cycle enzymes are located, and where CO2 released by decarboxylation of the four-carbon acids is then fixed by RuBisCO activity to the three-carbon sugar 3-phosphoglyceric acids. The physical separation of RuBisCO from the oxygen-generating light reactions reduces photorespiration and increases CO2 fixation and, thus, photosynthetic capacity of the leaf. C4 plants can produce more sugar than C3 plants in conditions of high light and temperature.