Microbodies

Microbodies are present in eukaryotic cells, particularly in the cytoplasm. Microbodies function as specialized organelles within eukaryotic cells, primarily involved in lipid metabolism, detoxification, and the breakdown of fatty acids. Some examples of microbodies include peroxisomes and glyoxysomes. In this article, we will understand microbodies structure and function in detail.

Microbodies

Microbodies are tiny, specialized organelles found in the cytoplasm of eukaryotic cells. They play an important role in metabolism. Microbodies have an approximately spherical form but can take many forms. Surrounded by a single membrane, they contain compounds-degrading enzymes. Microbodies primarily focus lies on tasks such as breaking down fats, detoxifying harmful substances, and managing cellular energy. Among some microbodies are Woronin bodies, peroxisomes, glycosomes, and glyoxysomes.

Also Read: Cell Organelles

Structure of Microbodies

These "microbodies" are the bodily components found in a cell's cytoplasm. They are also referred to as cytosomes. A microbody is typically a spherical vesicle with a diameter of between 0.2 and 1.5 micrometres. Microbodies can be seen in a cell cytoplasm, however, they can only be viewed under an electron microscope. They are surrounded by a single phospholipid bilayer membrane and have an intracellular protein and enzyme matrix. Thy lack any genetic material that would allow them to self-replicate.

Also Read: Types of Protein: Structure, Function and Classification

Function of Microbodies

Some of the functions of microbodies are:

• Microbodies participate in numerous cell biochemical processes.
• The breakdown of lipids, amino acids, alcohol, etc. is made possible by the enzymes found in microbodies.
• They participate in plants' photorespiration.
• In microbodies, peroxides are detoxified.

👁 Lysosome

Types of Microbodies

The enzymes found in microbodies participate in the beginning or intermediate stages of a variety of biochemical processes taking place inside the cell. These enzymes promote the oxidation of fatty acids, alcohols, and amino acids. Microbodies often play a big role in plants' photorespiration and peroxide detoxification. Microbodies are divided into categories based on their functions. Important microbodies include the following: Woronin bodies, Glyoxysomes, Peroxisomes, and Glycosomes.

Peroxisomes

This organelle was identified by Christian de Duve in 1965. It was found with the use of the fractionation method.

• Cells from plants and animals both contain these microbodies.
• Organelles such as the endoplasmic reticulum, mitochondria, and chloroplasts are situated in close proximity to it.
• It is found in all eukaryotic cells and is particularly prevalent in the liver and kidney cells.
• The endoplasmic reticulum gave rise to the 70–100 peroxisomes that make up the photosynthetic cell.
• The peroxisomes can vary in size, shape, and diameter.
• The interior matrix of these structures, which might be granular or contain uniformly spaced fibrils, is covered by the outer membrane.
• Oxidative enzymes such as urate oxidase, hydroxy acid oxidase, and hydroxy acid oxidase are present in these microbodies.
• The process results in hydrogen peroxide, which another enzyme known as catalase instantly metabolises.

Also Read: Peroxisomes: Definition, Structure, Diagram & Functions

Structure of Peroxisomes

The structure of peroxisomes is:

• Using a catalase cytochemical reaction, peroxisomes—membrane-bound, spherical or ovoid organelles—can be identified in cells. Larger peroxisomes can be seen in the laboratory in the hepatocytes.
• The endoplasmic reticulum is frequently in its immediate surrounding.
• In stain preparations, they showed minute organelles with a diameter of 0.1 to m.
• Urate oxidase is found in the nucleoid and crystal structure of the core. On the other hand, human cell peroxisomes are nucleoid-free.

👁 Peroxisomes

Function of Peroxisomes

The functions include:

• The long-chain fatty acids are oxidised by enzymes found in peroxisomes.
• They take part in the manufacture of cholesterol by using their enzyme.
• Peroxisomes are engaged in the detoxification of chemicals that injure the cells in the body, like ethanol and hydrogen peroxide.
• The synthesis of plasmalogen is started by certain of its peroxisomal enzymes. The majority of myelin's phospholipids are made up of this material.

Glyoxysomes

Glyoxysomes were discovered by Breidenbach in 1967. These organelles are regarded as a distinct variety of peroxisomes.

• These are the microbodies that contain the fatty acid oxidation and glyoxylate pathway enzymes.
• These are the biggest microbodies and are only present in plants.
• Glyoxysomes are the structures that are present in the cells of some fungi and the fatty seeds that are germination (such as castor, groundnut, etc.) up until and unless the stored fat is eaten.
• Enzymes are found inside glyoxysomes, which have a single outer membrane.
• Acetyl CoA is created when fatty acids are oxidized. The glyoxylate cycle breaks down the latter to create carbs.
• After serving their purpose, the glyoxysomes are changed into peroxisomes.
• For the purpose of lipid mobilisation and breakdown, these structures emerge in senescent plant tissues.

Glycosome

The glycosome is a membrane-enclosed organelle that has glycolytic enzymes and proteinaceous matrix. Glycosomes have crucial role in glucose metabolism, particularly glycolysis, within certain organisms such as protozoa like Leishmania and Trypanosoma. These organelles facilitate the breakdown of glucose to produce energy and intermediates for biosynthetic pathways, contributing to the overall metabolic functions of the cell. According to theory, it descended from the peroxisome. Peroxisomal and glycolysis enzymes are found in glycosomes.

Woronin Body

The woronin body is a dense core microbody produced from peroxisomes that are shielded by a double-layered membrane. It was named after Mikhail Stepanovich Woronin, a Russian botanist. In filamentous Ascomycota, it is found close to the septae that divide the hyphal compartments. These microbodies primary function is to close off the septal pores after hyphal injury. It prevents cytoplasm from being lost in the areas of damage. The woronin bodies can range in size from 100 nm to more than 1 μm. In certain species, they are visible under a light microscope.

Peroxisome Biogenesis Disorders

Peroxisome biogenesis disorders (PBDs) are a group of genetic conditions that affect the formation and function of peroxisomes. Two common types of PBDs are Zellweger syndrome spectrum (ZSS) disorders and rhizomelic chondrodysplasia punctata (RCDP) type 1. These disorders happen because of changes, called mutations, in at least 14 different genes known as PEX genes. These genes make proteins that help build and multiply peroxisomes. When these genes do not work correctly, it causes problems with peroxisome function which leads to Peroxisome biogenesis disorders (PBDs).

ZSS disorders are linked to mutations in thirteen of these genes. As PBDs can happen in different ways, it's difficult to know which gene is causing the problem in a person with ZSS. Scientists use different methods including examining the most commonly changed parts of PEX genes, to find out which gene is affected. DNA testing is very useful for diagnosing PBDs. It can help find out if someone is a carrier of the disorder, do prenatal testing for families at risk, and understand how genes relate to symptoms. This information can improve the care and support given to patients with PBDs and their families.

Conclusion - Microbodies

In conclusion, microbodies, including peroxisomes and glyoxysomes, are impofrtant cell organelles found in cytoplasm of. The microbodies function include lipid metabolism, detoxification, and fatty acid breakdown. While peroxisomes detoxify harmful substances like hydrogen peroxide and participate in fatty acid oxidation, glyoxysomes are involved in converting fatty acids into carbohydrates. Understanding the structure and function of these microbodies highlights the fundamental cellular processes which are crucial for metabolism and cellular homeostasis.

Also Read:

• Centrosomes
• Ribosomes and Inclusion Bodies
• Ribosomes
• Useful Microorganisms