lecture 11 ( Intracellular Compartments and Protein Transport) Flashcards
What is the main difference between phagocytosis and receptor mediated Endocytosis?
In the phagocytosis the macromolecules contain receptors that binds to the receptors of the plasma membrane while the receptor mediated endocytosis molecules immediately binds to the receptor.
Does the surface area and volume of the cell change when it goes through endocytosis?
NO, cell’s total surface area and volume remains the same, because it’s balanced by exocytosis
in the endocytic pathway there are three process:
pinocytosis - phagocytosis - receptor mediated endocytosis
True or False: pinocytosis and phagocytosis happens in all cells
False, only few cells can do phagocytosis
What does the mutation in LDL receptor proteins cause?
It causes the development of atherosclerosis which is caused by cholesterol accumulation in the blood
What are the cells that undergo phagocytosis?
Macrophages and white blood cell neutrophils
What is phagosome?
It’s the vesicles formed from the process phagocytosis
What is the Tricks evolved from Mycobacteria tuberculosis that subvert the system?
It’s can inhabit the membrane fusion that unites the phagosome with lysosome and instead it will engulf the organism or bacteria which will cause growth on multiplicationof it
True or False: Receptor mediated endocytosis is used to take up essential Metabolites such as vitamin B12 and iron…
TRUE 
Where are the Endocytosis macromolecules stored in:
endosome
What is the function of endosomal compartment?
It is the main sorting station in the inward In the endocytic pathway
What is the difference between endosomal compartment and trans Golgi?
Trans golgi is an outward Secretory pathway, while EC is an inward Endocytic pathway
Endosomes has acidic or basic or neutral environment.
ACIDIC
Why must the endosome have an acidic Environment?
Because The acidic pH plays a crucial part in The sorting process causing many receptors to release their particles
How does the environment of the endosome stay acidic?
ATP driven H+ proton pump is what keeps it acidic it’s pumps H+ into the Endosome lumen from the cytosol
Type of receptor recycling method:
1) returns to the orginal domain on the plasma membrane like LDL receptor
2) travels to the lysosome for degradation
3) proceed to a different domain of the plasma membrane or travelling from one extercellular space to another (transcytosis)
where does the digestion of cargo protein and marcomolecules first occur?
in the late endosome and continues in the lysosome
lysosome contain ____ types of hydrolytic enzymes such as protein degrader, nucleic acid, oligosaccharide, and lipids
40
pH of lysosome _____
pH of cytosol ____
5.0
7.2
Where did the enzymes inside the lysosome come from?
it is synthesized in the ER and cis golgi and transported to trans golgi which packges it and deliever it through clatherin vesicles to lysosome
How is the enzyme synthesized?
1) In the ER and cis golgi the enzyme is tagged with mannose 6-phosphate
2) then it is recognized by mannose 6-phosphate receptor in the trans golgi
3) then it is packaged in vesicles with the receptor to the lysosome via late endosome
Why does the lysosomal membrane contain transporters?
it allows the final degraded product to be transfered to the cytosol for usage
True or False: Lysosomal membrane proteins are highly glycoslayted
TRUE
what is Autophagy?
the process of which the cell consumes parts of it self by enclosing the organelle with double membrane then transporting it to the lysosome
