Short presentation

1. LYSOSOME
• Lysosomes are important cell organelle found with in eukaryotic cells.
• Due to their peculiar function, they are also known as “Suicidal Bags”
of the cell.
• The term was coined by Christian de Duve , a Belgian Biologist , who
discovered it and got a Nobel Prize in 1974.

2. Definition
Lysosome are sphere-shaped sacs filled with hydrolytic enzymes that
have the capability to break down many types of biomolecules –
protein, nucleic acid, carbohydrates and lipids.

3. Structure
• Lysosome are membrane bound
organelle and contain LAMP and
LIMP and form a coat on inner
surface.
• The size of lysosome vary from
0.1micrometer to 1.2 micrometer.
• PH level of the lumen lies between
4.5 and 5. And maintained by
proton pump and chloride ion
channels.
• SNAREs protein control the fusion
process.

4. Why are lysosome known as suicidal bags ?
Sometimes, the digestive enzymes may end up damaging the
lysosome themselves, and this can cause the cell to die. This is termed
as autolysis. Hence lysosome are known as “suicidal bags” of the cell.

5. Function
• The key function of lysosomes is digestion and removal of waste.
Cellular debris or foreign particle are pulled in to the cell through the
process of endocytosis.
• On the other hand , discarded wastes and other substances
originating from with in the cell is digested by the process of
autophagocytosis.
• Besides breaking down biological polymers , lysosomes are also
involved in various other cell process such as counting discharged
materials, energy metabolism , cell signalling and restoration of
plasma membrane.

6. Enzyme Formation
• Lysosome comprise of over 60 different enzymes.
• They are synthesised in RER.
• After synthesis the enzyme are brought in from the Golgi Apparatus in
tiny vesicles or sacs , which then merges with bigger acidic vesicles.
• The enzyme produced especially for lysosomes are mixed with the
molecule mannose 6-phosphate making them get fixed appropriately
up to acidified vesicles.

7. Different enzymes present in lysosome
1. Phosphatase
2. Nucleases
3. Proteases
4. Lipid degrading enzyme
5. Sulphatases
6. Polysaccharides / mucopolysaccharides hydrolysing enzymes

8. Clinical Significance
• Production of enzymes of the lysosomes is organised by nuclear
genes.
• Any mutation in these genes may result in the emergence of over 30
divers human genetic ailments , which are collectively called
lysosomal storage diseases(LSD).
• When such a mutation occurs, the molecules accumulate with in the
cell and eventually kills it. This can lead to a cancer and a host of
other disease ranging from cardiovascular disease, neurogenerative
orders and ageing-associated ailments.

9. Some Neurogenital Disease
1. Niemann-Pick :- Dysfunction in fat metabolism.
2. Pompe disease:- Weakness to the heart and skeletal muscle.
3. Parkinson’s disease:- Aggregation of protein in brain.
4. Gaucher disease:- Lack of An enzyme glucoserebrosidase (GBA).