Role in Aging and Diseases
Start with the big picture
Free radicals have unpaired electrons and include superoxide, hydroxyl radical, and nitric oxide. ROS can arise from sources such as mitochondrial electron transport, enzyme activity, radiation, and inflammation. When ROS exceed antioxidant capacity, they can damage lipids, DNA, and proteins. The body counters this through enzymatic defenses, including superoxide dismutase, catalase, and glutathione peroxidase, as well as non-enzymatic antioxidants. The lesson connects accumulated cellular damage with theories of aging and examines disease pathways: ROS-related protein changes in neurodegeneration, LDL oxidation and endothelial effects in cardiovascular disease, DNA injury in cancer, and oxidative stress associated with diabetes. These connections provide a framework for understanding how redox imbalance can affect tissues over time.
What you'll learn
- Define free radicals and identify major biologic forms of ROS.
- Describe key sources of ROS and the cellular damage they can cause.
- Distinguish enzymatic and non-enzymatic antioxidant defenses.
- Explain how oxidative stress is linked to aging and disease processes.
- Recognize examples of ROS-related mechanisms in selected diseases.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
