Thread: Types of free radicals

Most free radicals are coming from oxygen atoms and are called Reactive Oxygen Species (ROS), such as superoxide ion, hydroxyl radical, hydrogen peroxide and singlet oxygen.

Superoxide ion (or reactive oxygen species) is an oxygen molecule with an extra electron. This free radical can cause damage to mitochondria , DNA and other molecules. Our body can neutralize superoxide ions by producing superoxide dismutase.

Hydroxyl radical is formed by the reduction of an oxygen molecule in the electron transport chain. It is a neutral (not charged) form of the hydroxide ion. Hydroxyl radicals are highly reactive and form an important part of radical biochemistry. Unlike superoxide the hydroxyl radical cannot be eliminated by an enzymatic reaction. Is has a very short half-life and will only react with molecules its vicinity. Because of its high reactivity it will damage most organic molecules such as carbohydrates, DNA, lipids and proteins.

Singlet oxygen is formed by ou immune system. Singlet oxygen causes oxidation of LDL cholesterol.

Hydrogen peroxide is not a free radical but it is involved in the production of many reactive oxygen species. Hydrogen peroxide is a byproduct of oxygen metabolism and is neutralized by peroxidases.

Sometimes reactive nitrogen atoms are involved and these free radicals grouped under Reactive Nitrogen Species (RNS). Nitric acid is the most important RNS. Some transitional metals, such as iron and copper, have many numbers of unpaired electrons and can also act as free radicals. These metals do not have that strong electron affinity but can easily accept and donate electrons.

This is a great post mikaela. I didn't know that there are different types of free radicals

Thanks for the information mikaela. Like what sasa said, it is important to know that there are different types of free radicals so we learn how to fight them. As we all know, foods and supplements with high amount of antioxidants is good for the body because they help our body get rid of these deadly free radicals.