L33 Flashcards
How do we form lysosomes?
From accumulation of particles in early endosomes, which then matures to lysosome
What is the function of Mannose-6-Phosphate?
For targeting hydrolytic enzymes from trans Golgi to early endosomes
Identify 3 disease that relates to lysosome storage
Hurler’s disease
I-Cell disease
Defect on accumulation of materials in lysosomes
What is the pH inside the lysosome?
~5
Why is the hydrolytic enzyme of lysosomes are membrane-bound?
To prevent the degradation of cells outside the lysosomes
How do endolysosomes turn back to lysosomes?
By degrading accumulated particles
How do we transport things from plasma membrane to golgi?
By endocytosis
Identify the transport pathways of particles to lysosomes
Phagocytosis
Endocytosis (early-late-lysosome)
Macropinocytosis
Autophagy
What is Autophagy?
Degradation of used organelles
What is kiss and run? And who is it for?
Kiss and run is for neurotransmitters
It is when the vesicles comes in contact with plasma membrane, it “kisses” the membrane enough to open and release transmitters, which then pinches off then goes back to Golgi
What form of transport mechanism does LDL take?
Endocytosis
What form of transport mechanism when we take particles toward plasma membrane?
Exocytosis
What is multivesicular bodies and what is it for?
It is when there is pinching off of membrane in early endosome, forming an internal vesicle inside the endosome itself
This is for efficient degradation of material
Identify the 2 pathways of exocytosis and what is the difference?
Constitutive (continuous) and signal-mediated (regulated)
Where does the secretory vesicles wait?
Near plasma membrane
Why is it important to quickly recycle secretory vesicle?
To avoid the enlargement of plasma membrane, thus taking out more transmitters
What is Hurler’s disease?
The defection of “alpha-L-iduronidase” that’s required to break down GAG chain
What is I-cell disease?
The defection of GlcNac phosphotransferase that adds M6P to hydrolytic enzyme
What does Lysosomal proteins get tagged with? And what is it for?
Gets tagged with Asn-linked N-linked oligosaccharides for protein folding
What is the removal of terminal glucose in protein folding for?
To allow recycling process and folding of protein
What is the signal patch for?
To determine the addition of M6P where glucosamine transferase binds
What is the N-acetyl glucosamine for?
To leave a phosphate group behind, thus adding a phosphate group to the M6
What are the key players of Lysosomal-targeting pathway?
M6P
Signal patch
Glucosamine transferase
N-acetyl glucosamine phosphate (NGP)
Where did M6P gets added?
In early cisternae of Golgi
