Opening Questions:
1. When you think of the word
FAT what do you think of ?
2. What happens to water on a
duck’s back?
3. Why?
Opening Question Answers
• 2. Water rolls of their
backs….
• 3. The reason is that they have
glands filled with oil on their
tails…
• As they clean themselves oil is
transferred to their feathers
• What do we know about oil and
water?
• They DO NOT mix
• So the oil acts as a repellent or
barrier to the water.
Learning Outcomes
• 1. Summarize the categories of
• lipids
• 2. Provide examples of their
biological functions
A. Lipids
• 1. All Lipids have 2 characteristics
in common:
• a. They are insoluble in water
because they contain nonpolar
hydrocarbon chains
• b. They have hydrophobic
functional groups
• Water fearing
• 2. Lipids make up molecules such
as:
• a. Fat ---• Bacon, lard and butter
• b. oils --• corn oil, olive oil….
• 3. Lipids have two primary
functions for the body:
• a. Long term energy use--• b. Insulation
*
*1. Fats and oils contain two
subunit molecules (monomers)
*a.GLYCEROL---MAIN TYPE
*1. contains three OH- groups
*2. These groups are polar
*3. They are soluble in water
*b. Fatty acids---MAIN TYPE
*1. Only contains carbons and
hydrogen (nonpolar)
*2. Also has a carboxyl group
attached at one end.
*(Insoluble)
C. Formation of
Fats and Oils
1. Fats and/or oils form when a
carboxyl group of THREE fatty
acids reacts with a OH group of
a glycerol.
2. As a result a fat molecule is
made as well as three water
molecules.

a. when WATER is created
during a reaction remember this
is called a dehydration synthesis
reaction (Condensation Rxn)
b. The fat or oil that forms is
called a TRIGLYCERIDE:
COMPLEX LIPID
1. during the process
remember 3 fatty acids attach
to 1 glycerol molecule
2. Triglycerides can store a lot
of energy
3. Thus the long term energy
storage

D. FATTY ACIDS
1. Most fatty acid
molecules contain 1618 carbon molecules
2. Fatty acids are
categorized 2 ways:
a. unsaturated
b. saturated
E. Difference between
Unsaturated and Saturated
Fatty Acid
1. Unsaturated fatty acids
contain double bonds
between some hydrogen
and carbon molecules
2. Because of this they stay
liquid at room
temperature…
Example: Oils
Unsaturated Fat
1. Saturated fatty acids contain
NO double bonds between
some hydrogen and carbon
molecules
2. Because of this they stay solid
at room temperature…
Example: Butter
Saturated Fat
1.
2.
These are formed when
hydrogen molecules are
added to fatty acids to make
them more saturated. (solid
at room temp.)
Because of this… trans fats
and saturated fats build up as
plaque in your blood vessels.
3. Plaque causes blood flow to
slow and ultimately causes
heart disease.
4. Unsaturated fats stay liquid
at room temperature so they
do not build up in the blood
vessels
Trans fats-----Saturated Fats
are BAD for you.
Unsaturated fats are good
for you.
F. Phospholipid Molecules
COMPLEX LIPID
1. Very unique molecule
2. Main component of the
cell membrane
3. Discuss in the next
chapter
G. Waxes
COMPLEX LIPID
1. A wax molecule is made up of
a long chain of fatty acid
AND
A long alcohol chain
2. Waxes are highly water proof
This characteristic allows
them to be good for
protecting organisms.
b. EXAMPLES
Earwax to keep microorganisms
out
Leaves have a wax cuticle to
keep moisture in.
a.
H. Steroids
Steroids are very UNIQUE
LIPID because they have a
carbon skeleton made of four
fused rings.
2. They do not contain fatty
acids
3. But like other lipids…they
are insoluble in water.
a.
Types of steroids
1. Cholesterol: main
component of animal cell
membranes
2. Male hormones
(testosterone)
3. Female hormones
(estrogen)
b. Anabolic steroids are
synthetically made
steroids
WARNING:
They may built muscle
Internal Organs have a hard
time
breaking
them
down
{
(unnatural)
So they destroy our internal
organs
Wrap it up…
1. Lipids are used for
long term energy and
insulation.
2. Types are:
a. Fats
b. Oils
c. Waxes
d. Steroids
3. There are two main tyoes of lipids:
a. Glycerol b. Fatty Acids
4. There are three categories of
Complex Lipids
a. Trigycerides b. Phospholipids
c. Waxes
5. The most unique lipids are Steroids