Question

A person applies hydrogen peroxide on his wound. This is to kill
A. Anaerobic bacteria
B. Aerobic bacteria
C. Fungi
D. Protozoa

Answer 1

Hint: 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.

Complete Answer:
Hydrogen peroxide ($H_2O_2$) has two hydrogen atoms and two oxygen atoms. It is used as an oxidising 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 oxidises and kills the anaerobic bacteria.

Side effects of hydrogen peroxide use:
- The oxidation destroys healthy skin cells.
- It also slow the healing process
- It worsens the scarring process by killing the healthy cells around the cut.
- Aerobic bacteria- These are the bacteria which needs 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 higher concentration.

Thus the correct answer is (A).

Additional Information: 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: 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.