Lecture 5 Membrane Structure: Lipid Components

Question 1

What is Diaglycerol (DAG)

Answer 1

glycerol + two fatty acids

Question 2

What is phosphatidic acid (PA)

Answer 2

DAG + phosphate

Question 3

What is lysophosphatidic acid (LPA)

Answer 3

PA but missing one fatty acid

Question 4

Phosphatidyl-ethanolamine (PE) and phosphatidyl-choline (PC) have what kind of charge?

Answer 4

They have a positive charged head but a net neutral composition

Question 5

Phosphatidyl-serine (PS) has what kind of charge?

Answer 5

A neutral head but a net negative lipid

Question 6

Why is phosphotidyl-inositol (PI) important?

Answer 6

it is important for signaling

Question 7

What are plasmalogens

Answer 7

They are located in the heart and brain. They have one of the fatty acid chains attached differently

Question 8

What is a sphingosine

Answer 8

a sphingolipid with one acyl chain

Question 9

What is ceramide?

Answer 9

a sphingosine + one fatty acid

Question 10

What is myelin

Answer 10

ceromide-phosphate -choline

Question 11

What are cerebrosides and gangoliosides

Answer 11

glycosphingolipids

Question 12

What is 3-cholesterol

Answer 12

It is not a phospholipid and it has a small head group

Question 13

What are leaflets

Answer 13

2 layers

Question 14

How is lateral mobility within a leaflet?

Answer 14

very good

Question 15

What are flippases

Answer 15

A proteins that flips a lipid from one leaflet to another

Question 16

Membrane fluidity organization: gel vs fluid

Answer 16

gel= well organized
fluid= not organized

Question 17

Membrane fluidity organization: short FA vs long FA (fatty acids)

Answer 17

shot FA move in fluid

long FA pack together

Question 18

Describe sphingolipid movement

Answer 18

They are long FA and group together

Question 19

Lipids rapids are ____ and contain _____ and _____

Answer 19

thick; sphingolipids and cholesterol

Question 20

How is membrane curvature affected by lipids

Answer 20

hydrophobic/hydrophilic parts are different diameters

the two leaflets curve in opposite directions

Question 21

Integral vs peripheral protein structure

Answer 21

Intergral proteins cannot be removed from the membrane

peripheral proteins can be removed from the membrane (removed by high amounts of salt/pH)

Question 22

Transmembrane proteins (integral or peripheral?)

Answer 22

Always integral

Question 23

What is a beta barrel

Answer 23

a round serias of beta sheets across a membrane

Question 24

what is porin

Answer 24

A beta barrel protein that makes pores in bacterial membranes

Question 25

What do PH domains bind?

Answer 25

phosphorylated PI’s (phosphotidyl-inositols)