H-C-H
H-C-H
H-C-H
H-C-H
H-C-H
HCH
H
h , c
C H
3
C H
C H
3
OH
C
D
CH
CH
3
A
B
C
HO
A
B
HO
Lipids • Figure 2.11
There are three classes of lipids:
a.
triglycerides,
b.
phospholipids, and
c.
steroids.
a.
Triglycerides
Glycerol
molecule
Three fatty acid molecules
H
I
H-C-O-
H-C-O-
I
H
OHHHHHHHHHHHHHHH
Il
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-H
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
HHHHHHHHHHHHHHH
Palmitic acid (C15H31COOH) + ^ H2O
(saturated)
OHHHHHHHHHHHHHHHHH
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
H-C-O-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
HHHHHHHHHHHHHHHHH
Stearic acid (C17H35COOH) +
(saturated)
OHHHHHHHH
,
I
I
I
I
I
I
I
I
I
f i
CCCCCCCCC
.........................
'V
,
HHHHHHH
Oleic acid (C17H33COOH) ^ H 2O
(monounsaturated)
b. P h o sp h o lip id s
Head
Phosphate
group
Glycerol
Polar head
Triglycerides consist of a
glycerol backbone and 3 fatty
acids.
The fatty acids may be saturated
(as in butter) or unsaturated (as
in cooking oil).
Simplified way to
draw a phospholipid
Tails
Phospholipids have a glycerol backbone, a
phosphate head, and two fatty acids.
Phospholipids have a polar head that is
hydrophilic and a non-polar tail that is
hydrophobic.
Phospholipids are the major constituents of
membranes found in cells.
Arrangement of phospholipids
in a portion of a cell membrane
Nonpolar tails
Polar
heads
Non-polar
tails
Polar
heads
Cell
membrane
c. Steroids
Cholesterol
4 rings
Estradiol
(an estrogen)
Steroids comprise the steroid
hormones, such as estrogens,
progesterone, testosterone,
and cortisol.
Estrogens and progesterone
are found in birth control pills
Cortisol and its derivatives,
like prednisone, are widely
used as anti-inflammatory
agents.
M lSO
pill
H2O
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