Difference Between Lysozyme and Lysosome

The key difference between lysozyme and lysosome is that the lysozyme is a proteolytic enzyme found in lysosomes that is capable of breaking proteins in the bacterial cell wall while the lysosome is an organelle found in cells that consists of a large variety digestive enzymes.

The cell is the basic living unit or an organism. It consists of different organelles such as mitochondria, nucleus, ribosome, Golgi bodies, endoplasmic reticulum, lysosome, etc. Each organelle performs its role for the overall cell functioning.

CONTENTS

1. Overview and Key Difference
2. What is Lysozyme
3. What is Lysosome
4. Similarities Between Lysozyme and Lysosome
5. Side by Side Comparison – Lysozyme vs Lysosome in Tabular Form
6. Summary

What is Lysozyme?

Lysozyme is a proteolytic enzyme found in the lysosomes. Hence, it is an antibacterial enzyme that breaks the bacterial cell walls. It is also known as muramidase or N-acetylmuramide glycanhydrolase, as lysozyme can hydrolyze the β-1,4-glycosidic bonds between NAG (N-acetylglucosamine) and NAM (N-acetylmuramic acid) in bacterial peptidoglycan layer. The tears, saliva, mucus, and human milk also have lysozyme enzymes. Hence, it inhibits the growth of bacteria in these fluids.

Lysozyme works at pH 5, and it is a thermally stable enzyme. Thus, they are ubiquitous in nature and produced by viruses, bacteria, phages, fungi, plants, and animals. Other than cleaving glycosidic bonds in peptidoglycan, lysozymes are able to cleave chitin because it possesses chitinase activity as well.

What is Lysosome?

Lysosome is one of the organelles found in plant and animal cells. It surrounds by a single membrane, and it contains a vast array of digestive enzymes. These enzymes involved in splitting most of the biological molecules such as proteins, carbohydrates, nucleic acids, fats, etc. in the cell. Therefore, it assists in destroying cell debris as well.

Furthermore, lysosomes involve in phagocytosis and autophagy. Among the proteolytic enzymes found in lysosomes, lysozymes are important, because, they are the enzymes capable of breaking bacterial proteins. Hence, they are important in the defense system. Lysosomes appear as dense spherical vacuoles. However, their sizes and shapes are not uniform. All of the lysosome enzymes are acid hydrolases. Thus, they work at the pH value of around 5.

What are the Similarities Between Lysozyme and Lysosome?

• Lysosomes contain lysozyme enzymes.
• Both lysozyme and lysosome enzymes work at pH 5.
• Lysozyme and Lysosome involve in the digestion of macromolecules.

What is the Difference Between Lysozyme and Lysosome?

Lysozyme is an enzyme found in different fluids including tear, mucus, saliva, human milk, etc. Lysosome is the cell organelle which consists of many digestive enzymes including lysozymes in the cell. Lysozyme enzyme is very important in fighting against bacteria as it has the ability to cleave bonds between NAG and NAM molecules of the peptidoglycan layer and destroy bacterial cell wall, especially in grams positive bacteria. Furthermore, lysozyme has the chitinase activity. The below infographic presents the difference between lysozyme and lysosome in tabular form.

Summary – Lysozyme vs Lysosome

Lysozyme is an important enzyme found in lysosomes. On the other hand, lysosome is an organelle in plant and animal cells. Moreover, lysosomes contain an array of digestive enzymes that aid the hydrolysis of different macromolecules inside the cells.  On the contrary, lysozyme is capable of cleaving glycosidic bonds between NAG and NAM molecules of the peptidoglycan layer of bacteria. Hence, they protect us from bacterial infections by destroying bacterial cell walls. This is the difference between lysozyme and lysosome.

Reference:

1.Cooper, Geoffrey M. “Lysosomes.” Advances in Pediatrics., U.S. National Library of Medicine, 1 Jan. 1970. Available here
2.“Lysozyme.” Egyptian Journal of Medical Human Genetics, Elsevier. Available here

Image Courtesy:

1.”Lysozymecrystals1″By Zanecrc – Own work, (CC BY-SA 4.0)  via Commons Wikimedia
2.”Lysosome21″By Gevictor – Own work, (CC BY-SA 3.0) via Commons Wikimedia