The Lipids: Triglycerides, Phospholipids, and Sterols Chapter 5.
Lipids: a large and varied group of organic compounds. Lipids include: Triglycerides.
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Transcript of Lipids: a large and varied group of organic compounds. Lipids include: Triglycerides.
Lipids: a large and varied group of organic compounds.
Lipids include:
Triglycerides
Lipids: a large and varied group of organic compounds.
Triglycerides include Phospholipids
Triglycerides consist of one molecule of glycerol bonded to three fatty acid molecules
Each fatty acid is linked to the glycerol molecule by an ester bond
C C C
H
OH
H
H H
H
OH OH
Glycerol
Hydroxyl groups
Fatty Acids:
General Formula: CH3 (CH2)n C
O
OH
Carboxyl group
H C C C
H
H
H H
H H
C C C
H
H
H H
H H
C
O
OH
CH3 CH2
H C C C
H
H
H H
H H
C C C
H
H
H H
H H
C
O
OH
Can be drawn as:
C
O
OH
A cis fatty acid
A trans fatty acid
LDL bad
HDL good
Forming a monoglyceride:
C
C
C
H OH
H
H
H
H
OH
OH
C
O
OH
C
C
C
H OH
H
H
H
H
OH
O C
O
+ H2O
Ester bond
Hydroxyl group and carboxyl group react
This is a condensation reaction
C
C
C
H O
H
H
H
H
O
O C
O
C
O
C
O
A triglyceride:
Can be drawn as:G
lyce
rol
Fatty acid
Fatty acid
Fatty acid
Ester bond
To split these ester bonds and separate a fatty acid from glycerol we need to add a molecule of water
C
C
C
H OH
H
H
H
H
OH
O C
O
+ H2O
C
C
C
H OH
H
H
H
H
OH
OH
C
O
OH
This is a hydrolysis reaction
Lipids: a large and varied group of organic compounds.
Lipids include: Cholesterol
Uses of Lipids in Living Things
1. Long-term energy stores
Human Adipose Tissue Plant Oils
2. Buoyancy for marine animals: lipids are less dense than water so help animals float
3. Insulation: a layer of fat beneath the skin cuts down heat loss
4. Production of water: fatty acids produce a lot of metabolic water when they are oxidised during respiration
e.g. C17H35COOH + 26 O2 18 CO2 + 18 H2O (a typical fatty acid)
Camels’ humps are made of fat