write a short note on lysosomes describing why they are known as suicide bags
Answers
Explanation:
Lysosomes are an important cell organelle found within eukaryotic animal cells. Due to their peculiar function, they are also known 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.
Lysosome Definition
Lysosomes are sphere-shaped sacs filled with hydrolytic enzymes that have the capability to break down many types of biomolecules.
In other words, lysosomes are membranous organelles whose specific function is to breakdown cellular wastes and debris by engulfing it with hydrolytic enzymes.
Lysosome in Plant Cell
Lysosomes are predominantly found in eukaryotic animal cells and are responsible for breaking down cellular debris. 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. Furthermore, findings suggest that these vacuoles possess hydrolytic enzymes similar to the ones found in animal cells.
So some botanists have challenged the definition of a vacuole. In other words, it sparked a controversy that pits the definition of the two cellular organelles, with some saying that both perform similar tasks.
Lysosomes Structure
Lysosomes are membrane-bound organelles and the area within the membrane is called the lumen, which contains the hydrolytic enzymes and other cellular debris.
Lysosomes
Lysosomes are membrane-bound sacs filled with hydrolytic enzymes
The pH level of the lumen lies between 4.5 and 5.0, which makes it quite acidic. It is almost comparable to the function of acids found in the stomach.
Besides breaking down biological polymers, lysosomes are also involved in various other cell processes such as counting discharged materials, energy metabolism, cell signalling, and restoration of the plasma membrane.
The sizes of lysosomes vary, with the largest ones measuring in more at than 1.2 μm. But they typically range from 0.1 μm to 0.6 μm.
Read more: Metabolism
Why are Lysosomes known as Suicidal Bags?
As stated before, lysosomes work as the waste discarding structures of the cell by processing undesirable materials and degrading them, both from the exterior of the cell and waste constituents inside the cell.
But sometimes, the digestive enzymes may end up damaging the lysosomes themselves, and this can 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 known as “Suicidal Bags” of the cell.
How do the Lysosomes function?
Cellular debris or foreign particles are pulled in to the cell through the process of endocytosis. The process of endocytosis happens when the cell membrane falls in on itself (invagination), creating a vacuole or a pouch around the external contents and then bringing those contents into the cell.
On the other hand, discarded wastes and other substances originating from within the cell is digested by the process of autophagocytosis or autophagy. The process of autophagy involves disassembly or degradation of the cellular components through a natural, regulated mechanism.
Where are Lysosomal Enzymes made?
Lysosomes comprise of over 50 different enzymes. They are synthesized in the rough endoplasmic reticulum.
Once synthesized, the enzymes are brought in from the Golgi apparatus in tiny vesicles or sacs, which then merges with bigger acidic vesicles.
The enzymes produced especially for lysosomes are mixed with the molecule mannose 6-phosphate making them get fixed appropriately up into acidified vesicles.
Lysosomal Disease
Production of enzymes of the lysosome is organized by nuclear genes. Nuclear genes are genes which are located within the nucleus of a cell, specifically in eukaryotes.
Any mutations in these genes may result 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 kills it. This can lead to cancer and a host of other diseases ranging from cardiovascular diseases, neurodegenerative disorders and ageing-associated ailments.
Hi mate..
Lysosomes are called as suicide bags because they contain digestive enzymes for intracellular digestion and waste disposal. Because of their ability to kill and digest cellular components, lysosomes are called suicide bags.
Hope it helps..
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