Membrane Flashcards Preview

CTO Quiz 1 > Membrane > Flashcards

Flashcards in Membrane Deck (17):
1

Functions of membrane

Signaling, transport, growth, motility, form organelles/compartments

2

Thickness of lipid bilayer

8-9 nm

3

Why does lipid bilayer form compartments?

Edges are energetically unfavorable, membrane will spontaneously form spheres and self-seals if broken

4

Selective permeability

Allows through small hydrophobic and uncharged molecules, larger, polar and charged particles require specific transport

5

Effect of saturation on membrane

Unsaturated fatty acids pack less densely and allow more fluidity, saturated chains decrease fluidity

6

Effect of cholesterol on membrane

Stiffens to distortion, decreases fluidity overall

7

Extracellular phospholipids

High in phosphatidylcholine, sphingomyelin, glycolipids

8

Intracellular phospholipids

Phosphatidylserine, phosphatidylethanolamine

9

How is membrane asymmetry maintained?

Lipids are generally added to cytosolic side, specific flippase can transfer to other half

10

Production of glycolipids

Produced in lumen of Golgi -> vesicle -> external layer (usually remain outside to form glycocalyx)

11

Categories of membrane proteins (4)

Transmembrane, monolayer, lipid linked, protein attached (integral includes trans and monolayer, peripheral is linked to lipid or protein)

12

Functions of transmembrane proteins (5)

Transport, receptors, anchors, enzymes, structural

13

Glycoprotein vs proteoglycan

Long carbohydrate chain is proteoglycan vs short chain is glycoprotein

14

Structural membrane proteins

Link membrane to cell, ex spectrin holds RBCs in shape

15

Function of glycocalyx

Mostly for recognition, ex lectin induces neutrophil migration during an infection

16

Restrictions on membrane protein movement

Attach to cytoskeleton, ECM, other cells, diffusion barriers, lipid rafts

17

Lipid rafts

Often hold proteins with complementary function, supported by sphingolipids, GPI, etc