Carbohydrates and lipids/fats are a very important part of our lives. They
have many similarities
and differences among each other, which distinguish
them from other macromolecules.
Carbohydrates, which include sugar and
their polymers, are used by organisms for fuel and
building material. They
come in many various forms going from simplicity to complexity. The
simplest, monosaccharides, compose of single sugars whose parts are arranged
around
asymmetric carbons. They generally have a molecular formula that is a
multiple of CH2O.
Glucose, the most common monosaccharide, is of central
importance in the chemistry of life.
Energy is stored in glucose materials
and extracts cells in the process of cellular respiration.
When two
monosaccharides join by covalently bonding through glycosidic linkage, they form
a
disaccharide, or double sugar. If more than two, such as hundreds and
thousands bond, they form
polysaccharides, or macromolecules.
There
are two main types of polysaccharides; storage and structural. Starch and
glycogen are
used for storage. In plants, starch is mainly used because if
it is synthesized, the plant can stock
an abundance of sugar. Starch can be
found in wheat, corn, rice, and other grains. Glycogen, on
the other hand,
is more extensively branched, therefore, it is stored by humans and animals.
Cellulose and chitin are the structural polysaccharides. Cellulose is a
tough component of the
walls in a plant cell. Structure is important since
that’s what organisms build strong materials from.
In parallel cellulose
molecules, the cell wall of a plant is held together by bonds which are
arranged in microfibrils. These strong cables help build walls for plants
and humans. Chitin,
conversely, mainly deals with strengthening the
arthropods’ exoskeletons.
The one thing all lipids have in common is the
fact that they are hydrophobic. The three families of
lipids are fats,
phospholipids, steroids. Glycerol, a form of alcohol, constructs fats when it is
mixed with fatty acids who consist of a carboxyl group on one end and
hydrocarbon on the other. Three
fatty acids linked to a glycerol make up
triacylglyceral. If the carbon atoms composing the tail don’t
form any
double bonds then a unsaturated fat is made. Respectfully, if one or more bonds
are
formed, the fat becomes saturated. Phospholipids are related to these
fats, but unlike
triacylglyceral, they have only two fatty acids. These
lipids make up bi-layers which form a
boundary between a cell and its
external environment. The result of this simply becomes the fact
that
phospholipids are important to cell membranes. When a carbon skeleton consists
of four
interconnected rings, the third type of lipid, steroid, is built.
Cholesterol, a manufacturer of
steroids, is one reason that sex hormones are
present in vertebrates. Because of that, it has
important functions even
though a high amount in the blood can contribute towards
atherosclerosis.
Both carbohydrates and fats are an important part of our everyday diets.
Almost everything you
eat contains carbohydrates. For example, while looking
at a nutrition label from Basic 4, a
common cereal, I noticed that a serving
of one cup contains 43g of total carbohydrates. Only 14 of
those grams come
from sugars, 4 come from fiber, and the remaining come from other
carbohydrates. The fat make up is 3g in total; 0g unsaturated, 1g
polyunsaturated, and 1g
monounsaturated. This fat intake is only 4% of the
daily value an average person should have,
and the carbohydrates are 14% of
the average. As you can tell, the advised amount of polymers
to be consumed
is rather high, therefore one conclusion can be drawn; they must be important!