C4 plants over C3 plants have a definite benefit from the bundled sheath. The sheath contributes to increased concentration of carbon dioxide in the leaves. We are aware of the competition between Rubisco and carbon dioxide and oxygen. We also know that the relative carbon dioxide and oxygen concentration affects the binding of this enzyme to a specific molecule. The high carbon dioxide concentration in the plants makes all Rubisco bind to carbon dioxide, and no oxygen binding exists.

In these plants, therefore, photorespiration does not occur.