Final answer:
Unstable molecules created by the metabolism of oxygen that can damage cell structures and DNA are known as reactive oxygen species (ROS), which include peroxides and free radicals. High concentrations of ROS lead to oxidative stress and associated health issues, but the body has antioxidants to mitigate their harmful effects.
Step-by-step explanation:
Oxygen in the body is metabolized to produce unstable molecules called reactive oxygen species (ROS), which can damage cell structures and DNA. These unstable molecules include peroxides and free radicals such as the hydroxyl radical (OH), hydrogen peroxide (H2O2), and superoxide (O2). ROS are created as byproducts of normal processes like mitochondrial ATP production and are essential in low concentrations for cellular functions such as signaling and immune responses. However, in high concentrations, they can cause oxidative damage to lipids, proteins, carbohydrates, and nucleic acids in cells. This can result in DNA damage leading to mutations and is associated with numerous diseases and aging. The body has mechanisms, including antioxidant enzymes and vitamins, to neutralize ROS and protect against cellular damage.