Does the C4 photosynthetic pathway utilize the enzyme Rubisco?
YES. The C4 pathway was discovered by M. D. Hatch and C. R. Slack, in Australia, in 1966, so it is sometimes called the Hatch-Slack pathway. In C3 plants, the first step in the light-independent reactions of photosynthesis involves the fixation of CO2 by the enzyme RuBisCo into 3-phosphoglycerate. However, due to the dual carboxylase / oxygenase activity of RuBisCo, an amount of the substrate is oxidized rather than carboxylated resulting in loss of substrate and consumption of energy, in what is known as photorespiration. In order to bypass the photorespiration pathway , C4 plants have developed a mechanism to efficiently deliver CO2 to the RuBisCO enzyme. They utilize their specific leaf anatomy where chloroplasts exist not only in the mesophyll cells in the outer part of their leaves but in the bundle sheath cells as well. Instead of direct fixation in the Calvin cycle, CO2 is converted to a 4-carbon organic acid which has the ability to regenerate CO2 in the chloroplasts of the bun
