Reactive oxygen species

Definition

Reactive oxygen species (ROS) are highly reactive molecules containing oxygen. They can damage cellular components such as DNA, proteins, and lipids.

5 Must Know Facts For Your Next Test

1. ROS are byproducts of normal cellular metabolism, particularly during aerobic respiration.
2. Common examples of ROS include superoxide anion (O2-), hydrogen peroxide (H2O2), and hydroxyl radical (OH).
3. Cells have developed antioxidant defenses like superoxide dismutase and catalase to neutralize ROS.
4. Excessive ROS production can lead to oxidative stress, which is harmful to cells and can result in cell death.
5. Certain microorganisms have evolved mechanisms to tolerate or detoxify ROS, allowing them to survive in oxygen-rich environments.

Review Questions

• What are reactive oxygen species and why are they significant in microbial growth?
• Name two common examples of reactive oxygen species.
• How do cells defend themselves against the damaging effects of ROS?

Related terms

Antioxidants: Molecules that neutralize reactive oxygen species to prevent cellular damage.

Oxidative Stress:

A condition resulting from an imbalance between ROS production and antioxidant defenses.

Superoxide Dismutase:

An enzyme that helps break down potentially harmful oxygen molecules in cells.