Which substance acts as an antioxidant within the respiratory chain?

Glutathione is recognized as a significant antioxidant within the respiratory chain. It plays an essential role in protecting cells from oxidative stress by neutralizing reactive oxygen species (ROS) that are produced during cellular respiration. The respiratory chain involves the transfer of electrons through a series of complexes in the mitochondria, which can lead to the formation of these potentially damaging free radicals.

Glutathione, a tripeptide composed of glutamine, cysteine, and glycine, effectively detoxifies these free radicals and helps maintain the cellular redox state, thereby supporting overall mitochondrial health and function. Its presence is critical for preserving the integrity of the cell’s membranes and proteins from oxidative damage, particularly in high-energy environments like those found in the mitochondria.

While Vitamin C and Beta-carotene are also known antioxidants, their roles are more related to neutralizing free radicals in other contexts and not specifically within the respiratory chain. Coenzyme Q10, although it plays a role in the electron transport chain as a carrier of electrons, does not function primarily as an antioxidant; rather, it assists in energy production. Thus, Glutathione is the correct answer based on its unique and vital role as an antioxidant specifically within the respiratory chain.