Lipids and Membranes

Question 1

Lipid

Answer 1

Insoluble in water but soluble in fat and organic solvents

Question 2

Biological function of lipids

Answer 2

Energy store
Precursors for vitamins
Steroid hormones
Bile acids
Membrane structure

Question 3

Triglycerides

Answer 3

AKA triacyclglycerols
3 fatty acids and glycerol

Question 4

Where are triglycerides stored?

Answer 4

In adipose tissue

Question 5

What are fatty acids?

Answer 5

Long chain aliphatic carboxylic acids

Question 6

Polyunsaturated fatty acid

Answer 6

Contains more than one double bond

Question 7

What does delta symbol show?

Answer 7

The position of the double bond relative to the carboxylate group

Question 8

What are phospholipids made of?

Answer 8

Glycerol
2 fatty acids
Phosphate containing head group

Question 9

What is the phosphatidyl group?

Answer 9

Phosphate glycerol and fatty acid component

Question 10

Common head groups

Answer 10

Choline
Serine
Ethanolamine
Inositol

Question 11

What are glycolipids made of?

Answer 11

Glycerol
2 fatty acids
Head group containing sugar

Question 12

Structure of steroids

Answer 12

Multi ring hydrophobic region
Hydrophilic region

Question 13

Composition of plasma membrane

Answer 13

H-L
Cholestrol
Phosphatidylcholines
Phosphatidylethanolamine
Sphingophospholipid
Carbohydrate

Question 14

Composition of outer mitochondrial membrane

Answer 14

45% Phosphatidylcholines
Others

Question 15

Composition of inner mitochondrial membrane

Answer 15

50% Phosphatidylcholines
Others

Question 16

Composition of nuclear membrane

Answer 16

55% Phosphatidylcholines
Others
10% Cholesterol

Question 17

PE

Answer 17

Phosphatidylethanolamine

Question 18

PC

Answer 18

Phosphatidylcholines

Question 19

What happens if there are more short chain fatty acids?

Answer 19

Fewer Van der Waals
Greater fluidity

Question 20

What happens due to kinks in unsaturated fatty acids?

Answer 20

Fewer Van der Waals
Greater fluidity

Question 21

What happens if there is greater cholesterol in the membrane?

Answer 21

Lower fluidity

Question 22

Types of membrane proteins

Answer 22

Structural
Receptors
Ion channels
Transporters
Enzymes

Question 23

How to remove peripheral proteins?

Answer 23

High salt, urea
Detergent
Phospholipases

Question 24

How to remove anchored proteins?

Answer 24

Detergent
Phospholipases

Question 25

How to remove integral proteins?

Answer 25

Detergent

Question 26

TSD

Answer 26

Tay Sachs Disease Autosomal recessive disease Causes accumulation of GM2 gangliosides in neurone lysosomes Defect in enzyme that breaks down GM2 gangliosides

Question 27

Trademark symptom of TSD

Answer 27

Macular cherry red spot during ophthalmology observation

Question 28

Breakdown of gangliosides

Answer 28

GM1 - GM2 - GM3 - Glc Cer - Cer - Sphingosine

Question 29

Amphipathic

Answer 29

Polar head group and non polar fatty acid tail

Question 30

What are anchored proteins?

Answer 30

Proteins that are covalently linked to a fatty acid chain or to surface glycolipid

Question 31

What are lipid rafts?

Answer 31

Ordered membrane microdomains linked to cell signalling that have high levels of cholesterol