EXAM1_L5_Membranes_yTransport Flashcards Preview

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Flashcards in EXAM1_L5_Membranes_yTransport Deck (13)
1

Which can pass the membrane?
O2, CO2, N2, Steroid Hormones, H20, EtOH, Glycerol, Urea, Glucose, Galactose, Fructose, H+, Na+, HCO3-, K+, Ca2+, Cl-, amino acids.

O2, CO2, N2, Steroids, H20, EtOH, Glycerol, Urea
NO CHARGE
SMALL
(small polar)

2

Carriers vs Channels

CHANNELS- passive only- no binding/interaction (straight through) ie: ACH-gated Na+ channel, intestinal GLUT-2

CARRIERS: Active or passive- binding/interaction
(ie- na-k-atpase; Na-driven-glucose carrier)

3

PC,PS,PI and PE are examples of ? Phosphatidylcholine example of ?

sphingolipids. glycerolphospholipids

4

Why is there no symmetry between cytosolic side and outside?

glycerolphospholipids and phingolipids don't naturally flip-flop. (Ie: PC on outside, PS on inside)
Flippases- used in apoptosis

5

which molecule is thought to naturally flipflop?

cholesterol

6

What increases membrane fluidity?

short Fatty acyl chains, poly-unsaturdated lipids, High temp

7

give an example of a membrane protein Covalently bound? what are they considered? is it normal?

-lipid-linked proteins (GGT). integral protein (inside)

-Peripheral proteins are hydrogen bonded (enzymes like sucrase, lactase, maltase etc).

Peripheral proteins hydrogen bonded can be washed off with water.

8

Where are membrane carbohydrates found?
What are membrane carbs made of?

Outside monolayer of Plasma membrane (ie glycocalyx)-
- made of glycolipids and glycoproteins (glycosylated proteins).

9

Roles of glycocalyx

- cell recognition
-slimy lubricant
-blood clotting, egg-sperm interaction

10

GLUT2 is what kind of protein?
How to get glucose in the enterocyte?

Glut2-Passive glucose Carrier protein (high to low).

-Na used to drive secondary active transport to move glucose against gradient into the cell.

11

What keeps Glut2 and Na_glucose carrier in place? What happens if disrupted?

Tight junctions keep cell polarity. If disruption, intercellular transport disrupted.

12

A person drinks poison suspected of disrupting cellular structure. superCool tests indicate claudin and occludin is present in urinalysis. What problems are expected?

A. decreased enterocyte absorption
b.

13

Peripheral proteins vs Integral proteins

Integral- transmembrane and lipid linked proteins (channels/carriers/ggt)
Peripheral- enzymes H-bound to integral proteins (sucrase, lactase, maltase)