Cell III

Question 1

Macropinocytosis

Answer 1

Big lips stick out to engulf object

Actin-based
Can be initiated by bacteria
Occurs in cells as they take up thyroglobulin and dendritic cells for immune surveillance

Question 2

Nonclathrin/noncaveolar endocytosis

Answer 2

No coating protein used

Cholera and shiga toxins

Question 3

Simeon 40

Answer 3

Uses caveolin to enter cells

Question 4

Clathrin-mediated endocytosis

Answer 4

Receptor binds to stimulus
Coat cytosolic side of receptor with clathrin
Use GTP (DYNAMIN - GTPase) to internalize complex
Forms coated vesicle
Coat sheds

LDL receptor works this way, protein hormones

Question 5

Clathrin-mediated Endocytosis - no receptors

Answer 5

Used in nerve cells
Cell releases neurotransmitters by fusing vesicle to membrane
Coats vesicle with clathrin, pulls vesicle back in, inserts NT, repeats

Question 6

Phagocytosis

Answer 6

Cell Eating
Generally mediated by receptors
Dependent on actin - no clathrin
Phagosomes
Fuse with lysosomes