Oxidative stress damages which cellular components?

Oxidative stress damages which cellular components?

• A. Proteins, lipids, and DNA.
• B. Only carbohydrates.
• C. Only ribosomal RNA.
• D. Only cell membranes.

Answer: (A)

Oxidative stress occurs when reactive oxygen species accumulate faster than the cell’s defenses can neutralize them, and these reactive molecules damage multiple macromolecules that are essential for life. The most vulnerable and informative targets are membrane lipids, proteins, and DNA. Lipids in membranes undergo lipid peroxidation, which disrupts membrane integrity and function. Proteins can be oxidized, leading to loss or alteration of enzyme activity, structural defects, and disrupted signaling. DNA can suffer base modifications, strand breaks, and cross-links, increasing mutations or triggering cell death. Together, damage to these three types of macromolecules explains why oxidative stress has broad and serious effects on cell viability, rather than being limited to carbohydrates, ribosomal RNA, or just membrane components. Antioxidant systems like SOD, catalase, and glutathione help prevent this damage, but when ROS overwhelm these defenses, the widespread harm to proteins, lipids, and DNA becomes evident.

Oxidative stress occurs when reactive oxygen species accumulate faster than the cell’s defenses can neutralize them, and these reactive molecules damage multiple macromolecules that are essential for life. The most vulnerable and informative targets are membrane lipids, proteins, and DNA. Lipids in membranes undergo lipid peroxidation, which disrupts membrane integrity and function. Proteins can be oxidized, leading to loss or alteration of enzyme activity, structural defects, and disrupted signaling. DNA can suffer base modifications, strand breaks, and cross-links, increasing mutations or triggering cell death. Together, damage to these three types of macromolecules explains why oxidative stress has broad and serious effects on cell viability, rather than being limited to carbohydrates, ribosomal RNA, or just membrane components. Antioxidant systems like SOD, catalase, and glutathione help prevent this damage, but when ROS overwhelm these defenses, the widespread harm to proteins, lipids, and DNA becomes evident.