Living organisms have large molecules (polymers) that
are important to life. These polymers are built from
building blocks called monomers. The chemical
reactions are joined together by a dehydration reaction
by removing molecule of water, called dehydration
synthesis reaction. Polymers can be broken down by
hydration reactions.
I. Carbohydrates (Saccharides)-sugars and starches
Level of structurea. monosaccharides
b. disaccharides
c. polysaccharides
a.Mononsaccharides-basic building block
-can 3,4,5,6, or 7 carbon backbone, trioses, tetroses,
pentoses, hexoses, etc.
-has the basic formula CnH2nOn n=#C backbone
-can be found in either a ring or a chain form- every
carbon has a hydroxyl group except for one
carbon that has carbonyl group.
Monosaccharides can be found as either
a ring or a chain structure.
b. Disaccharides
-two monosaccharides put together by
removing a molecule of water
-important disaccharides
sucrose-table sugar (glucose,
fructose)
maltose(2 glucose)
lactose- found in milk (glucose,
galactose)
The disaccharide, sucrose, can be
broken down to glucose and
fructose by a hydrolysis reaction or
by the addition of water. This is just
the opposite of previous reaction
c. Polysaccharides- polymers
containing many sugar units, usually
glucose. Can be linked together by dehydration. Important polysaccharides
-1.Starch - plants store excess sugars as starch.
-2. Cellulose-found in plant cell
walls.
-3. Glycogen-is animal starch.
-4. Chitin- polysaccharide made out of glucose. Found in cell walls of fungi and exoskeletons of
insects
Impt. functions of carbohydrates
1. Energy
2. Storage of energy
3. Structure
4. Packaging and lubrication
II. Lipids- class of organic compounds that are not water soluble. Lipids will NOT dissolve in
water.
Classes of Lipids
a. triglycerides-(fats and oils)
b. steroid
c. waxes
a. Triglycerides- are
composed of 3 fatty acids
and glycerolFatty acids
have a carboxyl group
and a hydrocarbon tail.
Palmic acid is a
saturated fatty acid with
the maximum amount of
hydrogens. Linoleic acid
is called an unsaturated
fatty acid.
This means that it
contains double
bonds and is missing some hydrogen. Synthesis of a
triglyceride involves 3 fatty acids and a glycerol.
Phospholipids are modified triglycerides. They are made
of two fatty acids, glycerol and a charged phosphate
group. They are an integral part of all cell membrane.
Phospholipids have a hydrophobic and hydrophilic part to
their structure.
Very seldom in illustrating
phospholipids, are all the atoms
shown. Instead they are illustrated
as such-Cell membrane has two
b. Steroids-are lipids. Their basic
layers of phospholipids as shown.
Cholesterol is an important
structure is four interlocking rings.
steroid. Cholesterol is a building
block for many hormones.
Cholesterol is found in many meats
and can damage veins and arteries
by clogging them. It is also an
important component of cell
membranes. c. Waxes-are even more water resistant and harder than fats. Insects usually have
waxy cuticles and so do the leaves of plants, including fruit skins and petal of flowers. You
produce wax in your ears.