C4 Plant

C4 Plant (Corn)

C4 ("four-carbon") plants are those "that use special compounds to gather carbon dioxide during photosynthesis", like corn. They extract more CO2 to prevent water loss, which is why most of these type of plants are found in dry, desert climates. C4 plants have adapted to behave this way because of a phenomenon called photorespiration. Photorespiration is when Rubisco, the enzyme in charge of binding CO2 to another molecule to transform it into sugar, begins grabbing more oxygen from the air when CO2 levels are too low. The result of this "is that sugar is burned up instead of being created". C4 Plants evolved to initially bind CO2 to a more efficient enzyme called PEP carboxylase instead. This enzyme allows CO2 to concentrate in bundle sheath cells surrounding the leaf vein to minimize photorespiration.