Cytology

Question 1

unit membrane

Answer 1

selective barrier around cells and some organelles (phospholipid bi-layer)

• histology: trilaminar under TEM
• biochemically: phospholipid bilayer

Question 2

another name for outer and inner leaflet

Answer 2

E-face (outer leaflet) - faces Extracellular space

P-face (inner leaflet) - faces ctoPlasm

Question 3

vesicular transport

Answer 3

active transport using membrane-bound vesicles

exocytosis: release of materials (aka secretion)
endocytosis: uptake of material

Question 4

What are the two types of exocytosis?

Answer 4

regulated and constitutive (always on)

Question 5

What is the signal to secrete regulated exocytosis?

Answer 5

calcium

Question 6

what three types of endocytosis are there?

Answer 6

pinocytosis: (drinking) generalized type of absorption (ALL CELLS).
Water, small dissolved solutes, forms pinocytotic vesicles, fuse with lysosomes for processing.
phagocytosis and Receptor mediated

Question 7

phagocytosis

Answer 7

Cell “EATING”
engulfment of macromolecules, cell debris, bacteria. Pseudopodia, Pattern recogniction receptors (PRRs).
Phagosome + lysosome = phagolysosome
Residual body

Question 8

what is the most selective endocytosis?

Answer 8

receptor mediated endocytosis. cargo proteins bind to cargo receptors causing material to be endocytosed, to make “coated vesicles”

Question 9

vesicular mitochondria

Answer 9

have tube-shaped cristae.
abundant in cells with lipid metabolism fn (e.g liver cells and steroid hormone producing cells)
(also appear during apoptosis)

Question 10

What do you usually see paired with vesicular mitochondria?

Answer 10

sER, lipid inclusions. . . fat metabolism

Question 11

What do you usually see with secretory vesicles

Answer 11

secretory vesicles are usually bunched up, all having uniform e- density. You can distinguish these bad boys with lipid inclusions because secretory vesicles will have the RER nearby, as well as euchromatin! (protein synthesis)