Chapter%205%20Lipid

1
Chapter 5 Lipid

• The mighty whales which swin in a swa of water,
  and have a sea of oil swimming in them

2
The function of lipid

•     Lipids are a class of biological molecules
  defined by low solubility in water and high
  solubility in nonpolar solvents.
• Function
• Energy
• membrane

3
5.1 Fatty Acids

• Fatty acids are either saturated (all
  carbon-carbon bonds are single bonds) or
  unsaturated (with one or more double bonds in the
  hydrocarbon chain). If a fatty acid has a single
  double bond, it is said to be monounsaturated,
  and if it has more than one, polyunsaturated.

4
A list of the most abundant fatty acids (M table
10.1)
5
(No Transcript)
6
(No Transcript)
7
Composition of natural fats (M table 10.2)
8
5.2 Triacylglycerol the fat tristearin (M10.2)
9
(No Transcript)
10
(No Transcript)
11
Whales and Arctic mammals rely on body fat for
both insulation and energy reserves.
12
Glycerophospholipids

• A 1,2-diacylglycerol that has a phosphate group
  esterified at carbon atom 3 of the glycerol
  backbone is a glycerophospholipid, also known as
  a phosphoglyceride or a glycerol phosphatide

13
Phosphatidic acid, the parent compound for
glycerophospholipids
14
The Most Common Phospholipids Phosphatidic
acidphosphatidyleth- anolamine, is
diphosphatidylglycerol
15
Structures of several glycerophospholipids and
space-filling models of phosphatidylcholine,
phosphatidylglycerol, and phosphatidylinositol.
16
A scheme of a micelle and a membrane (M10.5)
17
Soaps and detergents (M p 319)
SDS
Triton X-100
18
Phospholipids (M 10.6)
19
The hydrophilic groups of phospholipids (M10.7)
20
Structure of a typical membrane (M10.10)
21
Glycerophospholipid Degradation

• One of the Effects of Snake Venoms The venoms of
  poisonous snakes contain (among other things) a
  class of enzymes known as phospholipases, enzymes
  that cause the breakdown of phospholipids.

22
(No Transcript)
23
Ether Glycerophospholipids Ether
glycerophospholipids possess an ether linkage
instead of an acyl group at the C-1 position of
glycerol
24
A 1-alkyl 2-acyl-phosphatidylethanolamine (an
ether glycerophospholipid).
25

• The structure of 1-alkyl 2-acetyl-phosphatidylchol
  ine, also known as platelet activating factor or
  PAF

26

• The structure and a space-filling model of a
  choline plasmalogen. 

27
5.4 Other lipids

• Sphingolipids
• Waxs
• Terpens
• Cholesterol
• Steriod hormone

28
Sphingolipids often a hydrocarbon R group is
attached to the NH2 as in ceramide
29
General structure of glycosphingolipid (M p323)
30
A typical wax (M 10.4)
31
Cholesterol (M10.9)
32
Terpenes
33
(No Transcript)
34
(No Transcript)
35
Some other biologically active isoprenoid
compounds or derivatives.
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
Steroid Hormones
43
Separation and analysis of lipid

• Lipid extraction requires organic solvent
• Adsorption chromatography separates lipids of
  different polarity
• Gas-Liquid Chromatography resolves mixtures of
  volatile lipid derivatives
• Specific hydrolysis(mild acid or alkaline
  treatment) aids in determination of lipid
  structure
• Mass spectrometry reveals complete lipid
  structure

44
The End