What is a major function of selenium-dependent enzymes?

Selenium-dependent enzymes play a crucial role in protecting the body from oxidative stress by neutralizing reactive oxygen species (ROS). These enzymes, known as selenoenzymes, include glutathione peroxidases and thioredoxin reductases, which utilize selenium as a key component to maintain antioxidant defense systems. By converting harmful hydrogen peroxide and lipid peroxides into less reactive species, these enzymes help to prevent cellular damage that can lead to various diseases, including cancer and cardiovascular disorders.

The role of selenium as a cofactor in these enzyme systems emphasizes its importance in maintaining redox balance within cells, contributing to overall health and potentially enhancing athletic performance by reducing the risk of exercise-induced oxidative damage. This function underlines why the correct answer highlights the antioxidant capabilities of selenium-dependent enzymes, which are integral to cellular health and resilience against oxidative stress.