what protective enzyme is used to get rid of superoxide radical?
The correct answer and explanation is:
The protective enzyme used to get rid of the superoxide radical (O₂⁻•) is Superoxide Dismutase (SOD).
Here is an explanation:
Superoxide radical (O₂⁻•) is a highly reactive and potentially harmful molecule classified as a reactive oxygen species (ROS). It is produced naturally in biological systems as a byproduct of various metabolic processes, particularly cellular respiration in the mitochondria, but also by enzymes like NADPH oxidases. Due to its unpaired electron, the superoxide radical is unstable and can initiate damaging chain reactions, reacting with and oxidizing important cellular components such as DNA, proteins, and lipids, contributing to oxidative stress.
To protect cells from this damage, organisms have evolved enzymatic defense systems. Superoxide Dismutase (SOD) is the primary and most crucial enzyme in this defense line specifically targeting the superoxide radical. SOD catalyzes the dismutation (or disproportionation) of superoxide radicals. This reaction converts two superoxide radicals into molecular oxygen (O₂) and hydrogen peroxide (H₂O₂). The chemical reaction is typically represented as:
2 O₂⁻• + 2H⁺ → H₂O₂ + O₂
By catalyzing this reaction, SOD effectively neutralizes the highly reactive superoxide radical, preventing it from causing widespread cellular damage. While the product, hydrogen peroxide (H₂O₂), is still a reactive molecule, it is less dangerous than superoxide and can be further broken down into harmless water and oxygen by other enzymes such as Catalase and Glutathione Peroxidase, which act downstream of SOD in the cellular defense pathway.
Different forms of SOD exist in various cellular compartments where superoxide is generated: Cu/Zn-SOD is typically found in the cytoplasm and the intermembrane space of mitochondria, while Mn-SOD is located within the mitochondrial matrix. This strategic distribution allows SOD to rapidly scavenge superoxide radicals as soon as they are formed, playing a vital role in maintaining cellular health and preventing oxidative stress and its associated pathologies.