What role do antioxidants play in biological systems?

• A. Enhance free radical production
• B. Serve as primary energy sources
• C. Neutralize free radicals
• D. Construct cellular membranes

Answer: (C)

Antioxidants play a crucial role in biological systems by neutralizing free radicals. Free radicals are unstable molecules that can cause oxidative damage to cells, proteins, and DNA, leading to various diseases and aging. Antioxidants stabilize these free radicals by donating an electron, thereby preventing the free radicals from causing further cellular damage.

By countering the harmful effects of free radicals, antioxidants contribute to maintaining cellular integrity and function. They can be enzymes, such as catalase and superoxide dismutase, or non-enzymatic compounds, such as vitamins C and E, flavenoids, and other phytochemicals. This protective mechanism is vital for cellular homeostasis and overall health.

The other options do not accurately represent the primary functions of antioxidants in the biological context. For instance, while free radicals are often produced during cellular respiration and metabolic processes, antioxidative compounds do not enhance their production. Similarly, although energy sources are essential for cellular function, they do not correlate with the role of antioxidants. Additionally, constructing cellular membranes is primarily the function of lipids and proteins, rather than antioxidants.