Peroxisome - Definition, Structure and Function

What is Peroxisome?

 

The peroxisome is formerly known as a microbody.

Peroxisomes are organelles found in the eukaryotic cell. It is single membrane-bound organelles and does not have its own DNA (lacks genetic material). New Peroxisomes bud from pre-existing ones Peroxisomes.

Peroxisomes are small vesicles, oxidative organelles contain oxidized enzymes important for metabolic activity. It takes part in various oxidative processes.

 

 Check out here what are lysosomes and proteasomes?

 

Peroxisome vesicle contains oxidases and catalase that decompose hydrogen peroxide.

Peroxisomes play a crucial role in the oxidation of specific biomolecules.

The oxidation reactions produce hydrogen peroxide. It is potent toxic to the cell because it has the ability to react with many other molecules.

Peroxisomes contain enzymes such as catalase that convert hydrogen peroxide to water and oxygen and neutralize the toxicity.

In that way, peroxisomes provide a safe site for the oxidative metabolism of certain molecules.

 

In plants, peroxisomes prominent role in photosynthesis and seed germination.

 

 

Peroxisome Structure

 

 

 

Peroxisomes are small vesicles, single membrane-bound organelles found in the eukaryotic cells and do not have their own DNA.

The enzymes of peroxisomes involved in lipid metabolism are synthesized on free ribosomes and selectively imported to peroxisomes.

 

The phospholipids of peroxisomes are usually synthesized in SER (smooth Endoplasmic reticulum) and imported to peroxisomes, via phospholipid transfer proteins.

 

Proteins are also transported in peroxisomes, from the cytosol after translation.

 

Function of Peroxisomes

 

Major functions are- 

 

1. A major function of the peroxisome is the breakdown of very-long-chain fatty acids ( LCFA) through beta-oxidation (lipid metabolism).

 

2. Peroxisomes play an important role in lipid synthesis (production). It also contributes to the biosynthesis of membrane lipids known as plasmalogens. Plasmalogen is the most abundant phospholipid form in nervous tissue and myelin.

 

3. Peroxisomes contain enzymes that oxidize certain molecules such as fatty acids and amino acids.

 

4. It detoxifies harmful substances. For example, alcohol produces hydrogen peroxide.

 

5. Peroxisomes are found numerous in liver and kidney cells where they detoxify certain compounds and substances like alcohol.

 

6. Peroxisomes also help in the production of bile acids (bile acid synthesis). It is important for the absorption of fats and fat-soluble vitamins.