Transcript Lecture_1_Dr_Manar_1

are composed of thousands of smaller organic molecules
(Monomers) to form a long chain called (macromolecules)
* Poly = many;
-mer = part. A polymer is a large molecule
consisting of many smaller sub-units bonded together
called monomers
* Monomers are covalently linked to one another through
the removal of water (dehydration reaction) to form
polymers.
*
What is a polymer?
Polymer is a long molecule consists of a chain of similar building
molecules (monomers) covalently bounded together.
Polymers principles:
•
•
•
•
Carbohydrates
Lipids
Proteins
Nucleic acids
Q: How do monomers connect?
A: By dehydration reaction
One monomer
provides a
hydroxyl group
One monomer
provides a
hydrogyn group
Covalent Bond
Monomers
By Dehydration
Forms Covalent
bonds
Polymer
By Hydration
breaks Covalent
bonds
Polymer
Monomers
1. Carbohydrates:
Carbohydrates
Monosaccharaides
Disaccharides
Polysaccharides
Monosaccharaides
Based on the number of C in
the skeleton
Based on the location of C=O
Aldoses
(C=O) at the end
of C chain (e.g.
Glucose).
Ketoses
Triose
C=O is within
the C chain
(e.g.
Fructose).
(3C) e.g.
Glyceraldehy
de
Pentose
(5C): e.g.
Ribose.
Hexose
(6C): e.g.
Glucose,
Fructose and
Galactose
• The hydration reaction
disassembles the covalent
bonds in the polymer and
convert it to small monomers.
This reaction dominate the
Add water
digestive process
with the help of specific
enzymes.
• THIS REACTION NEEDS WATER.
• It happens when H and OH
(from the water) attaches
where the bond used to be.
Add water
• The dehydration reaction
convert the small monomers
into one large polymer.
• THIS REACTION PROVIDES
WATER.
• It happens when H atom from
one monomers attaches with
OH from another one to create
water and new polymer.
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Disaccharides
Consisted of 2 monosaccharide molecules during a
dehydration reaction.
e.g. Sucrose (table sugar): consists of Glucose + Fructose.
Polysaccharides
Storage
Starch (in plants)
consisted of

thousands of
glucose
molecules.
Structural
Glycogen (in
animals)
consisted of
thousands of
glucose
molecules.
Cellulose (in
plants)
consisted of
thousands of
glucose
molecules.
β
Chitin (in insects)
consisted of
thousands of
glucose molecules
with a N atom in
one end
It is consisted of β glucose molecules.
“Human cannot digest it, but some bacteria and
protozoa can”
It is the building material in insects.
It is consisted of thousands of glucose molecules and an N
atom at the end.
Consisted of few hundreds to few thousands of
monosaccharaides
• Storage: provides sugar by
hydrolysis
Human
can’t digest
it, but
Surgical
thread
some bacteria & protozoa
can
insects
• Structural: building materials
for the organism
Chitin
Cellulose (in Plants):
It is the building material of the
It forms the micro-fibrils and cell
cuticle in insects. It consists of
wall in plants & it consisted of
1000s of glucose with N atom at
beta glucose molecules.
the end.
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*
*
*
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Starch is a plant storage from of energy, easily
hydrolyzed to glucose units
Cellulose is a fiber-like structural material tough and insoluble - used in plant cell walls
Glycogen is a highly branched chain used by
animals to store energy in muscles and the liver.
Chitin is a polysaccharide used as a structural
material in arthropod exoskeleton and fungal
cell walls.
*
Proteins is a polymer of amino acids “ there are 2o different
amino acids” .
The proteins are consisted of Hydrogen atom, carboxyl
group, Amino acid and R group ( variable )
H
H
N
Amino
group
H
C
R
Side chain
C
O
OH
Carboxyl
group
Amino acids are joined together with peptide bond by
dehydration reaction.
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The repeated sequence (N-C-C) is the polypeptide backbone.
Amino Acids
Hydrophobic
the amino acids
that have
hydrophobic R
groups (nonpolar).
Hydrophilic
Ionized
the amino acids
that have polar R
groups, making
them
hydrophilic.
the amino acids
with functional
groups that are
charged
(ionized) at
cellular pH (7).
So, some R
groups are bases,
others are acids.
None Polar R Group
Polar R Group
Functional R Group
Lipids
Fats
store large
amounts of
energy
Phospholipids
steroids
major
components of
cell membranes
include
cholesterol and
certain
hormones
In a fat, three fatty acids
are joined to glycerol by
an ester linkage,
creating a triacylglycerol.
Lipids do not
form polymer
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In a fat, three fatty acids are joined to glycerol by an ester linkage
creating a triacylglycerol.
Phospholipids have two fatty acids attached to
glycerol and a phosphate group( Two tails and a
head ) the tails are hydrophobic and the head is
hydrophilic .
form sex hormones and Cholesterol
Saturated
1. Fats
 The
MostFatty
animal
acid
fats
components
are saturated.
are saturated
 They
(there
areissolid
no double
at room
bonds
temperature.
between the
carbons.
Saturated
Allfats-rich
C are linked
diet results
with H.inThus, it is
Atherosclerosis.
saturated with H
Un-saturated
These double bonds are formed by the
removal
of H atoms.
They
can
befish
synthetically

Most vegetable
fats
(oils)
and
fats are
converted
to saturated (solid) by adding H
unsaturated.
(Hydrogenation).

They are liquid at room temperature.
there is no double bonds between the
carbons
“ Most animals Fats are saturated” And they are
solid at the room temperature.
The double bonds are formed by removing the H atoms.
“ Most vegetables oils and fish oils are Un-saturated “ And they are
liquid at room temperature.
2.Saturated
1.unsaturated
Phospholipids
They have two fatty acids
Attached to glycerol
And a phosphate group
l-fah
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macromolecules
lipids
carbohydrates
Monosaccharid
es
Disaccharid
es
Polysaccharid
es
Fats
phospholipids
Nucleic
acids
*
Proteins
Amino
acids
steroids
Hydrophilic
Hydrophobic
ionized
*
*
Q1: Write whether each of the following statements is True (T) or False (F):
*
2-Polysaccharides are polymers with few hundred to few thousand monosaccharides
joined by peptide bond.
*
*
*
*
*
*
*
*
*
3- The glucose monomers of cellulose are in the a configuration.
*
1-The four classes of organic compounds- carbohydrates, proteins, lipids and nucleic
acids are called polymers.
4- Chitin is a structural polysaccharide.
5-Starch can be digested by humans.
6-Saturated fatty acids contain double bonds between carbon atoms.
7-Stored polysaccharides in animals are known as starch.
8-In cellulose, all glucose monomers are in Ɣconfiguration.
9-Lipids are not polymers.
10- Glycogen is built up of several units of glucose monomers.
11- DNA and RNA molecules contain a hexose sugar called fructose.
*
6-Based on the number of C, sugars are classified into:
*
a)- trioses
b)- pentoses
c)- hexoses
d)- all a, b and c
*
*
7-Which of the following polysaccharide is stored in plant cells:
a)- starch
b)- cellulose
c)- glycogen
*
d)- chitin
*
*
* 8-Polypeptides are formed when amino acids link together by:
*
d)- peptide *
a)- ionic bonds
b)- hydrogen bonds
c)- ester bonds
bonds
*
*
*
9-Sex hormones are:
a-steroids
c-phospholipids
b-fats
10-Saturated fats are:
a)- found in oils, and liquid at room temperature
b)- contain double bonds
*
*
c)- found in animal fats and solid at room temperature
*
d)- can be transformed into unsaturated fats by hydrogenation
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