Lysosomes Flashcards
What are lysosomes?
Small, tiny spherical sac-like structures formed by Golgi Apparatus at trans face.
How many membranes does lysosomes have
Single
lysosomes Discovered by
Christian de Duve
What are lysosomes called in plant cells?
Sphaerosomes
Size of lysosomes
0.2μ-0.8μ
How do lysosomes activate?
At acidic pH ( pH=5 )
How is the acidic pH is maintained?
Membrane of lysosome has H+ pump protein which actively pumps protons (H+) into the lumen(empty space) of lysosome, creating acidic pH
Lysosomes are highly polymorphic? Why
Polymorphic means has many forms…this is because they have different physiological states.
What are the types of lysosomes?
- Primary lysosomes
- Secondary lysosomes
- Tertiary lysosomes
- Autophagy vacuoles
Which is the freshly formed lysosome also k/a storage granules and has enzymes in inactive form?
Primary lysosomes
1° lysosome+ phagosome = ?
And
Autophagosomes are?
1° lysosome + phagosome= heterophagosome.
Autophagosomes are lysosomes containing cell organelles to be digested.
What contains undigested material?
Residual bodies/ residual lysosomes
How is the undigested material eliminated?
By Exocytosis/ cell vomiting.
Functions of lysosomes?
- Intercellular digestion
- Extracellular digestion
- Autolysis
What is Autophagy?
Digestion of old/dead cell organelle.
It takes place during starvation of cell.
What is heterophagy?
It includes Endocytosis which further includes
* Phagocytosis - engulfment of food material in solid form
-cell eating
-phagosome
* Pinocytosis - engulfment of food material in liquid form
- cell drinking
- pinosome
What is Extracellular digestion?
Digestion/ breakdown occur outside the cell.
WBCs contain large number of lysosomes.
What is Autolysis?
Sometimes, all lysosomes of a cell burst to dissolve the cell completely, it is called Autolysis.
That’s why lysosomes are also called suicidal bags.
For eg:- during metamorphosis, lysosomes digest the tail of tadpole using cathepsin lysosome.
