Endocytosis, Lysosomes, & Trafficking

Question 0

Endocytosis

Answer 0

Includes pinocytosis (non-specific mechanism for uptake of fluids & solutes, does not involve receptors). 2 subcategories- macro and micropinocytosis

Question 1

Trafficking

Answer 1

The mechanisms by which materials are sorted and transferred between different cellular components

Question 2

Receptor mediated Endocytosis

Answer 2

Specific binding of certain molecules (ligands); uptake is therefore selective; fluid is also taken up along with the ligand

Question 3

Phagocytosis

Answer 3

“Cell eating”; process whereby larger insoluble particles, microorganism, or even entire cells are ingested via large endocytotic vesicles called phagosomes

Question 4

Endosomes

Answer 4

Consist of small vesicles or endosomal tubules and multivesicular bodies; site at which cellular material to be delivered to lysosomes is transported to lysosomes

Question 5

Early endosomes

Answer 5

Complicated structures that have numerous intermediates & sub-categories

Question 6

Late endosomes

Answer 6

Can assume a tubular or ovoid shape or spherical with small vesicles inside multivesicular bodies. They are structures that connect the endocytotic pathway with the lysosomal system.

Question 7

Primary lysosomes

Answer 7

Derived from Golgi and are membranous bags of hydrolytic enzymes. They function at an acidic ph of 5. Membranes of lysosomes are resistant to digestion because of their proteins are highly glycosylated

Question 8

Secondary lysosomes

Answer 8

Combination of the contents of an endosome and primary lysosome

Question 9

Heterophagy

Answer 9

Digestion of substances imported into a cell from the external environment (ex. Bacteria and foreign material)

Question 10

Autophagy

Answer 10

Degradation of organelles in an otherwise healthy cell

Question 11

Residual bodies

Answer 11

Indigestible residues of lysosomal activity associated with normal wear and tear, & accumulate with advancing age in the form of lipofuscin pigment