Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOC 341 > Lecture 4: Membrane Structure and Function > Flashcards

Lecture 4: Membrane Structure and Function Flashcards

1
Q

Most abundant membrane lipids are ____

A

phospholipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Membranes are held together by ___ interactions

A

noncovalent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What two structures do lipids form?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What lipid types have a cylinder shape?

A

Normal phospholipids, PC, PS, PI, PG, sphingomyelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What types of lipids have an inverted cone shape?

A

Lysolipids, acyl-CoAs, detergents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which lipids have a cone shape?

A

Diacylglycerol, Phosphatidic acid, unsaturated PE, fatty acids, ceremide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the four types of lipid movements in a membrane?

A

Lateral diffusion, flexion, rotation, flip-flop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name typical membrane proteins.

A
  • Glycerophospholipids

– PS, PE, PC, PI

• Sphingolipids

– Sphingomyelin (SM)

  • Cholesterol
  • Glycolipids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does cholesterol affect membranes?

A
  • Presence decreases fluidity of nearby lipids (less permeable)
  • Inhibits crystallization (lowers phase transition temperature)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What’s the structure of cholesterol?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does cholesterol pack in lipids?

A

It packs between fatty acid tails of the hydrophobic core of a bilayer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Glycolipids

A
  • Special sugar-containing lipids
  • Found exclusively on noncytosolic side
  • Tend to self-associate (lipid rafts)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Functions of glycolipids

A
  • protection of cell surface
  • electrical effects
  • cell recognition and adhesion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Glycolipid structure

A

They have a short carbohydrate chain covalently attached and this is exposed on the outer surface of the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are phospholipases?

A

A phospholipase is an enzyme that hydrolyzes phospholipids into fatty acids and other lipophilic substances.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Lipid Rafts

A
  • often rich in sphingolipids and cholesterol
  • longer, saturated chains of sphingolipids cause membrane thickening
  • arrangement recruits particular proteins and facilitates their transport or function as a group
17
Q

How are lipid droplets formed?

A

Storage form of lipids, usually triacylglycerol cores and cholesterol esters surrounded by a monolayer with a few proteins. They are thought to form from a “swelling” of the ER.

18
Q

Phospholipid assymetry

A
  • SM, PC, and glycolipids in outer leaflet (nuetral)
  • PE and PS in inner leaflet (charged, net negative)
19
Q

What type of membrane protein is this?

A

Peripheral membrane proteins

20
Q

What type of membrane protein is this?

A

PIG tail (GPI anchor)

21
Q

What type of membrane protein is this?

A

Covalent lipid attachment

22
Q

What type of membrane protein is this?

A

antipathic α-helix

23
Q

What type of membrane protein is this?

A

β-barrel

24
Q

What type of membrane protein is this?

A

Multipass α-helix

25
Q

What type of membrane protein is this?

A

Single pass α-helix

26
Q

Name three post-translational attachments to the membrane

A

Myristoyl anchor (14 carbons)

Palmitoyl anchor (16 carbons)

Farnesyl anchor (15 carbons)

27
Q

Which residues are preferentially hydrophobic?

A

Preferentially hydrophobic residues: Leu, Ile, Val, Ala, Phe

28
Q

Where are membrane-spanning beta barrels usully found in the cell?

A

bacterial, chloroplast, and mitochondrial membranes

29
Q

What are some common detergents?

A

SDS, Triton X-100, ß-octylglucoside

30
Q

What does CMC stand for?

A

Critical micellar concentration

31
Q

How do detergents dissolve membranes?

A
32
Q

Solubilization and reconstitution of a membrane protein

A
33
Q

___ create diffusion barriers for lipids, creating cells ____ membranes on different sides of the cell

A

Tight junctions, asymmetrical

ex- epithelial cells

34
Q

How does this protein shape the membrane?

A

Hydrophobic region of protein wedges into membrane, displacing lipid head groups and causing curvature

35
Q

How does this protein shape the membrane?

A

protein is curved and can bind to lipid head groups causing membrane to curve with it

36
Q

How does this protein shape the membrane?

A

protein binds to and therefor clusters lipids with big head groups, this induces curvature

BIOC 341 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions