lecture 11 ( Intracellular Compartments and Protein Transport)

Question 1

What is the main difference between phagocytosis and receptor mediated Endocytosis?

Answer 1

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.

Question 2

Does the surface area and volume of the cell change when it goes through endocytosis?

Answer 2

NO, cell’s total surface area and volume remains the same, because it’s balanced by exocytosis

Question 3

in the endocytic pathway there are three process:

Answer 3

pinocytosis - phagocytosis - receptor mediated endocytosis

Question 4

True or False: pinocytosis and phagocytosis happens in all cells

Answer 4

False, only few cells can do phagocytosis

Question 5

What does the mutation in LDL receptor proteins cause?

Answer 5

It causes the development of atherosclerosis which is caused by cholesterol accumulation in the blood

Question 6

What are the cells that undergo phagocytosis?

Answer 6

Macrophages and white blood cell neutrophils

Question 7

What is phagosome?

Answer 7

It’s the vesicles formed from the process phagocytosis

Question 8

What is the Tricks evolved from Mycobacteria tuberculosis that subvert the system?

Answer 8

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

Question 9

True or False: Receptor mediated endocytosis is used to take up essential Metabolites such as vitamin B12 and iron…

Answer 9

TRUE 

Question 10

Where are the Endocytosis macromolecules stored in:

Answer 10

endosome

Question 11

What is the function of endosomal compartment?

Answer 11

It is the main sorting station in the inward In the endocytic pathway

Question 12

What is the difference between endosomal compartment and trans Golgi?

Answer 12

Trans golgi is an outward Secretory pathway, while EC is an inward Endocytic pathway

Question 13

Endosomes has acidic or basic or neutral environment.

Answer 13

ACIDIC

Question 14

Why must the endosome have an acidic Environment?

Answer 14

Because The acidic pH plays a crucial part in The sorting process causing many receptors to release their particles

Question 15

How does the environment of the endosome stay acidic?

Answer 15

ATP driven H+ proton pump is what keeps it acidic it’s pumps H+ into the Endosome lumen from the cytosol

Question 16

Type of receptor recycling method:

Answer 16

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)

Question 17

where does the digestion of cargo protein and marcomolecules first occur?

Answer 17

in the late endosome and continues in the lysosome

Question 18

lysosome contain ____ types of hydrolytic enzymes such as protein degrader, nucleic acid, oligosaccharide, and lipids

Answer 18

40

Question 19

pH of lysosome _____
pH of cytosol ____

Answer 19

5.0
7.2

Question 20

Where did the enzymes inside the lysosome come from?

Answer 20

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

Question 21

How is the enzyme synthesized?

Answer 21

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

Question 22

Why does the lysosomal membrane contain transporters?

Answer 22

it allows the final degraded product to be transfered to the cytosol for usage

Question 23

True or False: Lysosomal membrane proteins are highly glycoslayted

Answer 23

TRUE

Question 24

what is Autophagy?

Answer 24

the process of which the cell consumes parts of it self by enclosing the organelle with double membrane then transporting it to the lysosome