lipids

Question 1

what are the 5 main classes of lipid?

Answer 1

Free fatty acids
Triacylglycerols
Phospholipids
Glycolipids 
Steroids

Question 2

fatty acid structure

Answer 2

Hydrocarbon chains with a terminal carboxylic acid group.

Can be saturated or unsaturated

Question 3

where and in what form are fatty acids stored?

Answer 3

Fatty acids are stored in adipocytes in form of triacylglycerol compounds

Question 4

structure of triacylglycerol compounds/ triglycerides

Answer 4

3 fatty acids linked to a glycerol molecule through ester linkages which help to neutralise COO- and keep pH normal

Question 5

glycerol structure

Answer 5

propane-1,2,3-triole

3 carbon alcohol

Question 6

what are the components of Phospholipids?

Answer 6

1. One or more fatty acid
2. Platform to which fatty acids attached/backbone
3. Phosphate
4. Alcohol (attached to phosphate)

Question 7

Name 2 type of phospholipids

Answer 7

Phosphoglycerides

Sphingolipids e.g sphingomyelin

Question 8

Phosphogylceride structure and bond location

Answer 8

Glycerol backbone
2 fatty acid chains
Phosphorylated alcohol
OH groups at C1 & C2 of glycerol backbone esterified to carboxylic groups of 2 fatty acid chains
C3 OH of glycerol backbone esterified to phosphoric acid (PO3^(2-)

Question 9

What is the simple base that major groups of phosphoglycerides can be generated from

Answer 9

Phosphatidate (diacylglycerol-3-phosphate)

Question 10

How can the major groups of phosphoglycerides be generated from a Phosphatidate?

Answer 10

formed by ester linkages between phosphoryl group of phosphatidate and hydroxyl groups of other molecules e.g serine

Question 11

Structure of sphingosine

2-amino-4-trans-octadecene-1,3-diol

Answer 11

18 carbon amino alcohol group with an unsaturated hydrocarbon chain.
Primary part of sphingolipids

Question 12

Sphingomyelin structure

Answer 12

1. sphingosine backbone
2. Fatty acid
3. phosphocholine

Amino group (NH3+) linked to fatty acid by amide bond 
OH of sphingosine has phosphoryl choline attached by ester linkage

Question 13

glycolipid structure

Answer 13

1. Sphingosine backbone
2. fatty acid
3. sugar unit/carbohydrate e.g glucose, galactose

amino group of sphingosine backbone acylated by fatty acid (peptide bond) (similar to sphingomyelin) ( i think)
OH group of sphingosine linked to sugar(s) unit/carb

Question 14

ceramide

Answer 14

sphingosine and fatty acid

Question 15

cerebroside

Answer 15

ceramide with a single sugar residue at the 1-hydroxyl moiety.

Question 16

Roles of Steroids

Answer 16

1. structural roles in membrane
2. formation of bile salts to aid fat digestion
3. building blocks of hormone synthesis

Question 17

Structure of cholesterol - common steroid

Answer 17

4 linked hydrocarbon rings
Hydrocarbon tail linked to steroid at one end
OH group attached to other end

Question 18

what does the OH group at one end of the steroid molecule mark cholesterol as?

Answer 18

A sterole