Chapter 11: Membrane Structure Flashcards

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1
Q

Membrane Composition

A

lipids and proteins

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2
Q

Integral proteins

A

directly attached to membrane

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3
Q

Peripheral

A

loosely associated with membrane

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4
Q

The rearrangement of the phospholipid bilayer favors what?

A
  • repair of damage
  • formation of a closed compartment ( which is more favorable)
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5
Q

Liposomes structure

A

phospholipid bilayer and aqueous interior

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6
Q

How can phospholipids move?

A
  • lateral diffusion
    -flexion
    -rotation
    -flip-floping sides ( rarely occurs)
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7
Q

Phospholipid affect on membrane fluidity

A

-fatty acid chain length (shorter = more fluid)
-fatty acid
chain saturation (cis double bond = more fluid)

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8
Q

Sterol affect on membrane fluidity

A

Cholesterol ( high concentration more fluid)
- if most fatty acids are unsaturated then cholesterol creates less fluidity

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9
Q

Temperature affect on membrane fluidity

A

high temp ( high fluidity)
low temp ( more rigid)

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10
Q

is cholesterol amphipathic

A

yes

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11
Q

What is the pattern of mature membranes

A

asymmetrical

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12
Q

1st step of membrane synthesis

A

in the smooth ER phospholipids are added no the cytosolic face

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13
Q

2nd Step of membrane synthesis

A

scramblases randomly flip phospholipids from one face of the membrane to the other in the ER

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14
Q

3rd Step of membrane synthesis

A

Flippases move specific phospholipids from the extracellular face to the cytosolic face in the Golgi. Floppases move phospholipids from the cytosolic face to the extracellular face of the Golgi

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15
Q

Where do glycolipids obtain their sugar?

A

inside the Golgi

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16
Q

How can integral membrane proteins be removed from membranes?

A

using detergents

17
Q

What happens when multiple amphipathic alpha helices associate?

A

form a hydrophilic pore ( integral membrane protein)

18
Q

What can a large curved beta sheet form?

A

beta barrel that spans the membrane

19
Q

Beta barrel structure

A

hydrophobic exterior and water filled interior (integral membrane protein)

20
Q

What do detergents do?

A

disrupt hydrophobic associations

21
Q

Properties of detergents

A

-Amphipathic
-Single hydrophobic chain
-Monolayer micelles

22
Q

Glycoprotein

A

protein with short, covalently attached oligosaccharide

23
Q

Proteoglycan

A

protein with one or more long oligosaccharides

24
Q

Glycolipid

A

lipid with covalently attached oligosaccharide

25
Q

Carbohydrate layer of cell surface composition

A

Glycoprotein, Proteoglycan, Glycolipid

26
Q

Carbohydrate later of cell surface function

A

protection from chemical and mechanical damage
- cell to cell recognition

27
Q

Ligands for lectins

A

proteins that bind oligosaccharide chains

28
Q

Glycocalyx

A

carbohydrate layer

29
Q

What is lectin binding responsible for?

A

recruitment of white blood cells to site of infection

30
Q

Cell Cortex

A

framework of proteins that attaches to membrane proteins, restricting their mobility

31
Q

What do tight junctions preserve?

A

the asymmetric distribution of membrane proteins