Lipids lecture 1

Question 1

Lipids features

Answer 1

1. Water insoluble
2. Varied structures
3. Fatty acids or isoprene units
4. Hydrophobic or amphipathic

Question 2

Functions of lipids

Answer 2

1. energy storage
2. Membrane components
3. Thermal insulation
4. Protective surfaces
5. Cell surface markers
6. Regulation of metabolism
7. Signalling molecules

Question 3

Examples of lipids made from fatty acids

Answer 3

Triacylglycerols
Eicosanoids
Waxes
Sphingolipids
Glycerophospholipids
Glycosphingolipids

Question 4

Examples of lipids made from isoprene units

Answer 4

Steroids
lipid vitamins
terpenes

Question 5

Unsaturated fatty acids

Answer 5

• Double bonds
• Low melting points
• liquid at room temp

Question 6

Saturated fatty acids

Answer 6

• NO double bonds
  -Higher melting point
• solid at room temp

Question 7

Triacylglycerols features

Answer 7

1 glycerol molecule + 3 fatty acid chains
Primary lipid found in adipose tissue (fat cells)
ester bonds

Question 8

Glycerphospholipids

Answer 8

1 glycerol + 2 fatty acid chains + phosphate group + x (rest of polar head eg choline)
Most abundant lipid found in membranes

Question 9

Lipid bilayer features

Answer 9

Non covalent interactions between lipid molecules - flexible and self-sealing
Define external boundaries of cells and seperate cellular compartments

Question 10

Types of proteins found in bilayer

Answer 10

Peripheral - outside
Integral - inside
lipid anchored
transport proteins

Question 11

Sphingolipids

Answer 11

Glycerol + fatty acid chains + amino group
Second most abundant lipid in membranes
particularly found in tissues of the central nervous system

Question 12

Ceramide

Answer 12

Glycerol + fatty acid chain + Amino group with other FA chain attatched

Question 13

Glycosphingolipids

Answer 13

Glycerol + FA chain + amino group with FA chain + Sugar (Eg galactose)
Example - ganglioside

Question 14

Waxes

Answer 14

NON polar esters
Long FA chain + long chain alcohol
water insoluble + high melting point
Widely distributed in nature - waterproof and protective

Question 15

Eicosanoids - Oxygenated derivatives of polyunsaturated C20 FA

Answer 15

a) Arachidonic acid
b) Prostaglandin - Constrictions of blood vessels
c) Thromboxane - clotting
d) leukotriene - smooth muscle contraction

Question 16

Chemical name for an isoprene unit

Answer 16

2- methyl- 1,3 - butadiene

Question 17

Cholesterol

Answer 17

Found in lipid bilayer to modulate fluidity

Question 18

Cholesteryl ester

Answer 18

for storage