Antioxidants

Definition

Antioxidants are molecules that inhibit the oxidation of other molecules, preventing or delaying the damage caused by free radicals and reactive oxygen species. They play a crucial role in maintaining cellular health and protecting against various diseases.

5 Must Know Facts For Your Next Test

1. Antioxidants work by neutralizing free radicals and reactive oxygen species, preventing them from causing harm to cells and biomolecules.
2. Common dietary antioxidants include vitamins C and E, carotenoids, flavonoids, and polyphenols, which are found in fruits, vegetables, and other plant-based foods.
3. Antioxidants can inhibit the initiation or propagation of radical chain reactions, chelate metal ions, or scavenge free radicals, thereby protecting cells from oxidative damage.
4. Phenols, a class of organic compounds with a hydroxyl group attached to an aromatic ring, are potent antioxidants due to their ability to donate hydrogen atoms or electrons to stabilize free radicals.
5. Antioxidants play a crucial role in mitigating the effects of radical reactions, which are implicated in the development of various diseases, including cancer, cardiovascular disease, and neurodegenerative disorders.

Review Questions

• Explain the role of antioxidants in radical reactions (Topic 6.6 Radical Reactions).
  • Antioxidants are essential in the context of radical reactions because they can neutralize and stabilize free radicals and reactive oxygen species, which are highly reactive and can initiate and propagate radical chain reactions that cause cellular damage. By donating hydrogen atoms or electrons to these unstable molecules, antioxidants can interrupt the radical chain reaction, preventing the propagation of further radical species and the resulting oxidative stress on biomolecules such as lipids, proteins, and DNA.
• Describe the relationship between phenols and antioxidant activity (Topic 17.9 Phenols and Their Uses).
  • Phenols, a class of organic compounds with a hydroxyl group attached to an aromatic ring, are potent antioxidants due to their ability to donate hydrogen atoms or electrons to stabilize free radicals. The aromatic structure of phenols allows for the delocalization of unpaired electrons, making them effective at scavenging and neutralizing reactive species. Many naturally occurring antioxidants, such as flavonoids and polyphenols found in fruits, vegetables, and other plant-based foods, are phenolic compounds that play a crucial role in protecting cells from oxidative damage.
• Evaluate the significance of antioxidants in maintaining cellular health and preventing disease development.
  • Antioxidants are essential for maintaining cellular homeostasis and preventing the development of various diseases. By neutralizing free radicals and reactive oxygen species, antioxidants mitigate the effects of oxidative stress, which is a key factor in the pathogenesis of numerous conditions, including cancer, cardiovascular disease, neurodegenerative disorders, and chronic inflammatory diseases. Antioxidants protect biomolecules like lipids, proteins, and DNA from oxidative damage, preserving their structure and function, and supporting overall cellular health. The importance of antioxidants is underscored by the growing body of research highlighting their potential therapeutic and preventive applications in the management of a wide range of health conditions.

Related terms

Free Radicals: Highly reactive molecules that contain unpaired electrons, causing them to readily participate in chemical reactions that can damage cells.

Reactive Oxygen Species (ROS): Chemically reactive molecules containing oxygen, including hydrogen peroxide, superoxide, and hydroxyl radicals, which can cause oxidative stress and cellular damage.

Oxidative Stress: An imbalance between the production of free radicals and antioxidants in the body, leading to potential cellular and tissue damage.