In C₄ plants, CO₂ in the mesophyll cell reacts with _________ to form oxaloacetate while in the bundle sheath cell, _________ undergoes decarboxylation to pyruvate.

Question

Quizplus · Accepted Answer

In C4 plants, CO2 is initially fixed into a 4-carbon compound in mesophyll cells by the enzyme PEP carboxylase, which forms oxaloacetate. The oxaloacetate is then transported to the bundle sheath cells where it is decarboxylated to pyruvate, which then enters the normal Calvin cycle. The 4-carbon compound in mesophyll cells is usually malate formed from CO2 and phosphoenolpyruvate. Therefore, the correct choices are PEP or phosphoenolpyruvate for the first blank and malate for the second blank. The only option that includes both correctly is D.

In C4 Plants, CO2 in the Mesophyll Cell Reacts with _________

In C₄ Plants, CO₂ in the Mesophyll Cell Reacts with _________