Lysosomes

Lysosomes are an important cell organelle found within eukaryotic animal cells. Due to their peculiar function, they're also referred to as the Suicide bags of the cell. The term was coined by Christian de Duve, a Belgian biologist, who discovered it and ultimately got a Nobel Prize in Medicine or Physiology in the year 1974.

Definition of Lysosomes 

“Lysosomes can be defined as the sphere-shaped sacs which when combined with hydrolytic enzymes have the potential to churn down many kinds of biomolecules. Lysosomes are membranous organelles which function to breakdown cellular wastes and debris by immersing it with hydrolytic enzymes. 

Structure of Lysosomes 

Lysosomes are membrane-bound organelles and therefore the area within the membrane is called the lumen, which contains the hydrolytic enzymes and other cellular debris.

Have a look at the diagram to understand the lysosome structure within a cell more specifically. 

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With the pH value of 4.5 and 5.0, the lumen becomes more acidic. It is almost comparable to the function of acids found in the stomach. 

Metabolism, Cell signalling, restoring of the cell membrane, energy metabolism and counting the discharged materials are some of the functions involved in cell processes. The sizes of lysosomes vary, with the most important ones measuring in addition at more than 1.2 μm. They also range from 0.1 μm to 0.6 μm. 

Why are Lysosomes known as Suicidal Bags?

As stated before, lysosomes work because the waste discarding structures of the cell by processing undesirable materials and degrading them, both from the outside of the cell and waste constituents inside the cell. But sometimes, the digestive enzymes may find yourself damaging the lysosomes themselves, and this will cause the cell to die. This is termed as autolysis, where auto means self and lysis means the disintegration of the cell by the destruction of its cell membrane .Hence, lysosomes are mentioned as Suicidal Bags of the cell.

How do the Lysosome function?

Digestion and removal of waste are the prime function of Lysosomes. Cellular debris or foreign particles are pulled into the cell through the process of endocytosis. The process of endocytosis occurs when the cell membrane functions invagination, creating a vacuole or a pouch around the external contents then bringing those contents into the cell. On the other hand, discarded wastes and other substances originating from within the cell are digested by the process of autophagocytosis or autophagy. The process of autophagy leads to disassembly or degradation of the cellular components through a natural, regulated mechanism. 

Where are Lysosomal Enzymes made?

Lysosomes comprise over 50 different enzymes. They are synthesized in the rough endoplasmic reticulum. Once synthesized, the enzymes are brought in from the Golgi body in tiny vesicles or sacs, which then merges with bigger acidic vesicles. The enzymes produced for lysosomes are mixed with the molecule mannose 6-phosphate making them fixed appropriately up into acidified vesicles. 

Lysosomal Disease

Nuclear genes perform a function of production of enzymes. Nuclear genes are genes which are located within the nucleus of a cell, specifically in eukaryotes. Any mutations within the genes may end in the emergence of over 30 diverse human genetic ailments, which are collectively called lysosomal storage diseases (LSD). When such a mutation occurs, the molecules accumulate within the cell and eventually kill it. This can lead to cancer and a host of other diseases ranging from cardiovascular diseases, neurodegenerative disorders and ageing-associated ailments.

Lysosome in Plant Cell

Lysosomes are predominantly found in eukaryotic animal cells and are liable for breaking down cellular debris. The role of lysosomes is undertaken by the vacuoles as traditional cell biology dictates in plants. Furthermore, findings suggest that these vacuoles possess hydrolytic enzymes almost like those found in animal cells. So some botanists have challenged the definition of a vacuole. In other words, it sparked an issue that pits the definition of the 2 cellular organelles, with some saying that both perform similar tasks.

FAQ (Frequently Asked Questions)

1. What are Lysosomes?

Lysosomes are sphere-shaped sacs which when combined with hydrolytic enzymes that have the potential to churn down many kinds of biomolecules.

2. Where are Lysosomal Enzymes made?

Lysosomes comprise over 50 different enzymes. They are synthesized in the rough endoplasmic reticulum. Once synthesized, the enzymes are brought in from the Golgi body in tiny vesicles or sacs, which then merges with bigger acidic vesicles.

3. Who coined the term Suicide Bags for Lysosomes?

The term was coined by Christian de Duve, a Belgian biologist, who discovered it and ultimately got a Nobel Prize in Medicine or Physiology in the year 1974.

4. What is the role of Lysosomes in plants?

In plants, the role of lysosomes is undertaken by the vacuoles as traditional cell biology dictates. However, recent discoveries point out that the function of vacuoles is quite similar to the functions of a lysosome in animal cells.

5. Why are lysosomes known as Suicidal Bags?

As stated before, lysosomes work because the waste discarding structures of the cell by processing undesirable materials and degrading them, both from the outside of the cell and waste constituents inside the cell. But sometimes, the digestive enzymes may find yourself damaging the lysosomes themselves, and this will cause the cell to die. This is termed as autolysis, where “auto” means “self” and “lysis” means “the disintegration of the cell by the destruction of its cell membrane“.Hence, lysosomes are mentioned as “Suicidal Bags” of the cell.