How is hydrogen peroxide antimicrobial?

Hint: We know that Hydrogen peroxide works as a disinfectant which destroys the essential germ cells and deactivates the wide range of microorganisms like bacteria, fungi, viruses and spores. Hydrogen peroxide is a highly unstable chemical compound. Two molecules of hydrogen combine with two molecules of oxygen to form hydrogen peroxide.

Complete answer:
Hydrogen peroxide $ ({{H}_{2}}{{O}_{2}}) $ has two hydrogen atoms and two oxygen atoms. It is used as an oxidizing agent as dissociation liberates nascent oxygen. When hydrogen peroxide comes in contact with the living cells, it breaks into water and oxygen due to the catalase activity. Hydrogen peroxide is used as an antiseptic as it kills bacteria by destroying their cell wall. It involves oxidation which oxidizes and kills the anaerobic bacteria. Side effects hydrogen peroxide use:
The oxidation destroys healthy skin cells. It also slows the healing process. It worsens the scarring process by killing the healthy cells around the cut. Aerobic bacteria. These are the bacteria which need oxygen to survive. Protozoa; The hydrogen peroxide is very harsh on protozoa. They can inhibit their life cycle. Fungi; It acts on fungus at very high concentration.
Hydrogen peroxide has basic uses as an oxidizer, bleaching agent and antiseptic. Concentrated hydrogen peroxide, also known as "high-test peroxide", is a reactive oxygen species and has been used as a propellant in rocket propulsions. As this compound is unstable, it slowly decomposes in the presence of light. Hydrogen peroxide is generally stored with a stabilizer in a weakly acidic solution since it is unstable. It can be found in biological systems including the human body. Peroxidases are the enzymes that use or decompose hydrogen peroxide. Our body naturally produces hydrogen peroxide when we metabolize food. Our body cells contain peroxisomes which contain catalase which decomposes the hydrogen peroxide to water and oxygen gas.

Note:
Remember that Hydrogen peroxide is an antifungal, antiviral and antibacterial agent. It is effective in treating molds. It works best as a surface cleaner but on application on the wounds can lead to tissue damage.