It is named after a scientist Hatch and slack pathway. basically this pathway helps plant to minimise water loss.. as we know that photosynthesis takes place in mesophyll cell but in this c4 pathway photosynthesis occurs in mesophyll as well as bundle sheath cell. mainly glucose molecule will form in bundle sheat cell.

The C4 pathway, also known as the Hatch and Slack pathway, is a type of carbon fixation pathway that some plants use to efficiently capture and utilize carbon dioxide (CO2) in order to produce energy-rich organic compounds. It is named after the scientists Marshall Davidson Hatch and Charles Roger Slack who first discovered and described this pathway.

The C4 pathway is primarily found in plants that live in hot and dry environments, such as tropical and subtropical regions. It is an adaptation that allows these plants to minimize water loss while maximizing photosynthetic efficiency.

Key Points:
- The C4 pathway involves two distinct types of cells in the plant's leaves: mesophyll cells and bundle sheath cells.
- In the mesophyll cells, an enzyme called phosphoenolpyruvate carboxylase (PEPC) captures CO2 and combines it with a three-carbon molecule called phosphoenolpyruvate (PEP) to form a four-carbon compound called oxaloacetate.
- The four-carbon compound is then converted into malate or aspartate and transported to the bundle sheath cells through plasmodesmata, small channels that connect the two types of cells.
- In the bundle sheath cells, the four-carbon compound is decarboxylated, releasing CO2, which is then used in the Calvin cycle, a series of reactions that convert CO2 into glucose and other carbohydrates.
- The released CO2 is recycled back to the mesophyll cells, where it is again captured by PEPC and converted into a four-carbon compound.
- This separation of initial CO2 capture and the Calvin cycle in different cells allows C4 plants to concentrate CO2 around the enzyme responsible for the Calvin cycle, minimizing the wasteful process of photorespiration and increasing photosynthetic efficiency.
- The C4 pathway requires ATP energy to function, which is provided by the light-dependent reactions of photosynthesis.
- Examples of C4 plants include corn, sugarcane, and many grasses.

In summary, the C4 pathway, also known as the Hatch and Slack pathway, is a specialized carbon fixation pathway found in certain plants. It allows these plants to efficiently capture and utilize carbon dioxide, making them well-adapted to hot and dry environments.