Lipids
are another type of organic molecule. Remember that organic means they
contain carbon (C) atoms. It's not like organic farming at all. When
you think of fats,
you should know that they are lipids. Lipids are also used to make steroids and
waxes. So, if you pick out some earwax and smell it, that's a lipid, too!
Waxes are used to
coat and protect things in nature. Bees make wax. It can be used for
structures, such as the bees' honeycombs. Your ears make wax. It is used to
protect the inside of your ear. Plants use wax to stop evaporation of
water from their leaves. There is a compound called cutin that you can
find in the plant cuticle covering the surface of leaves. It helps to seal and
protect plant structures. Don't worry about plants being able to breathe. There
are still small holes that let gases in and out of the leaves.
Steroids are found in animals within something called hormones. The basis
of a steroid molecule is a four-ring structure: one ring with five carbons and
three rings with six carbons. You may have heard of steroids in the news. Many
bodybuilders and athletes have used anabolic steroids to build muscle mass. The
steroids make their bodies add more muscle than they would normally be able to.
Those anabolic steroids help bodybuilders wind up stronger and bulkier (but not
faster). Steroids are also used in necessary medicines. Some help people with
acne, while others are used as muscle relaxers for injuries.
NOTE: Never take drugs to enhance your body.
Those athletes are actually hurting their bodies. They can't see it, because it
is slowly destroying their internal organs and not the muscles. When they get
older, they can have kidney and liver problems. Some even die.
Fat is also known as a triglyceride. It is made
up of a molecule known as glycerol that
is connected to one, two, or three fatty acids. Glycerol is the basis of all
fats and is made up of a three-carbon chain that connects the fatty acids
together. A fatty acid is
just a long chain of carbon atoms connected to each other.
There
are two kinds of fats, saturated and unsaturated. Unsaturated
fats have at least one double bond in one of the fatty acids. A double bond
happens when four electrons are shared or exchanged in a bond.
They are much stronger than single bonds with only two electrons. Saturated
fats have no double bonds.
Fats have a lot of energy stored up in their
molecular bonds. That's why the human body stores fat as an energy source. When
you have extra sugars in your system, your body converts them into fats. When
it needs extra fuel, your body breaks down the fat and uses the energy. Where one
molecule of sugar only gives a small amount of energy, a fat molecule gives off
many times more.