Download Macromolecules Biological Molecules Macromolecules

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Chapter 3
Palestine Polytechnic University
Department of Environmental Engineering
Technology
Course: Environment & Biological
Diversity
Instructor
Dr. Ayman Salah
Macromolecules
General points about biological
macromolecules
1- Functional groups give
specific properties to
molecules
• Organic molecules and
hydrocarbons
• Each functional group has
specific chemical properties,
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Macromolecules
Biological Molecules
• Four kinds of molecules found in living things:
proteins, carbohydrates, lipids, and nucleic
acids.
• Most of these biological molecules are large
polymers constructed by the covalent bonding
of smaller molecules called monomers.
Macromolecules
General points about biological macromolecules
2- Isomers have different arrangements of the same
atoms
3- The structures of macromolecules reflect their
functions
4- Most macromolecules are formed by
condensation and broken down by hydrolysis
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Macromolecules
Macromolecules
Proteins: Functions of proteins
Proteins: Chemical Structures of Proteins
1. Structural support (protein fibers)
2. Protection
3. Defense (antibodies)
4. transport (hemoglobin)
5. catalysis; Enzymes
6. Movement (actin, myosin)
7. Regulation (hormones)
8. Storage: (egg whites of birds, reptiles; seeds)
 The building blocks of proteins are
Amino Acids.
 The a.a. have both a carboxyl
functional group (COOH) and an
amino functional group (NH2)
attached to the same carbon atom,
called the α carbon.
 a hydrogen atom or a side chain is
attached to the a carbon atom.
The side chains also contain functional groups (Table 3.2
page 43)
Macromolecules
Proteins: Chemical Structures of Proteins
 Peptide bonds form the
backbone of a protein.
 N terminus and C
terminus
 Two or more a a bonded
together are called a
peptide
 (polypeptide & protein)
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Macromolecules
Proteins:
Levels of
protein
structure
• The primary
structure
determines
the further
structures
and the
function of
the protein
• The Tertiary structure and
the quaternary structure are
the functional forms
val his leu thr pro glu glu lys
• The primary structure
determines the further
structures and the function
of the protein
Macromolecules
Proteins: Environmental conditions affect protein
structure
 Some Conditions can not
break covalent bonds, but
can upset the weaker noncovalent interactions that
determine secondary and
tertiary structure, may
affect a protein's shape
and thus its function
 Denaturation
Couses: Increases in temperature , Alterations in pH,
High concentrations of polar substances
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Macromolecules
Carbohydrates
• carbohydrates are a group of molecules that
contain C, H and O in the ratio 1:2:1.
• The general formula for carbohydrates is
(CH2O)n.
• Functions of Carbohydrates:
 source of energy
 serve as carbon skeletons for biological
structures.
Macromolecules
Carbohydrates : Monosaccharides
• simple sugars have 3 to 7 carbon atoms.
• may be linear or form rings (Figure 3.1 3 page 50)
• Some are structural isomers; eg C6H12O6
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Macromolecules
Carbohydrates
• There are four categories of biologically
important carbohydrates:
1. Monosaccharides, simple sugars; glucose,
ribose, and fructose. the monomers for the larger
carbohydrates.
2. Disaccharides consist of two monosaccharides
linked together by covalent bonds.
3. Oligosaccharides (oligo, "several") are made up
of several (3-20) monosaccharides.
4. Polysaccharides (poly, "many"), such as starch,
glycogen, and cellulose
Macromolecules
Carbohydrates : Monosaccharides
• Glycosidic linkages bond monosaccharides
• The disaccharides, oligosaccharides, and
polysaccharides are all constructed from
monosaccharides that are covalently bonded
together by condensation reactions
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Macromolecules
Macromolecules
Carbohydrates : Disaccharides
Carbohydrates : Polysaccharides
• Disaccharides are composed of 2
monosaccharides.
 Sucrose: a glucose and a fructose molecule.
 lactose (milk sugar): glucose and galactose
 maltose :two glucose molecules.
• Polysaccharides
store energy
and provide
structural
materials
Macromolecules
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Macromolecules
Lipids
Lipids: Fats and oils
• Lipids are hydrocarbons that are insoluble in
water because of their many nonpolar covalent
bonds
• Several types of lipids with different functions:
1. Fats and oils store energy.
2. Phospholipids: in cell membrane structural.
3. The carotenoids : capture light energy.
4. Steroids: hormones and vitamins.
5. The fat in animal bodies : thermal insulation.
6. A lipid coating around nerves provides
electrical insulation.
7. Oil or wax on the surfaces of skin, and feathers
repels water.
• Fats and oils are triglycerides, also known as
simple lipids
fats are solid
at room
temperature
(20°C)
oils are liquid
at room
temperature.
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Macromolecules
Macromolecules
Lipids: Fats and oils
Lipids - Phospholipids
Saturated and Unsaturated Fats
• In saturated FA, all the
bonds between the carbon
atoms in the hydrocarbon
chain are single bondsthere are no double
bonds(all the bonds are
saturated with hydrogen
atoms).
• In unsaturated FA, the
hydrocarbon chain contains which is packed
one or more double bonds. tightly together?
• A phosphate-containing compounds replaces one
of the fatty acids of triglycerides
Macromolecules
Nucleic Acids
hydrophilic
“head” and
hydrophobi
c “tails
Macromolecules
Nucleic Acids
• NAs are polymers specialized
for the storage, transmission,
and use of genetic information
• There are two types of nucleic
acids:
1. DNA (deoxyribonucleic acid)
2. RNA (ribonucleic acid) .
Nucleic acids are composed of
monomers called nucleotides
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Two types of Nitrogen
bases occur in
nucleotides
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Macromolecules
Nucleic Acids
• In NA the backbone
of the macromolecule
consists of a chain of
alternating pentose
sugars and
phosphate groups
(sugar-phosphatesugar-phosphate).
• The nucleotides are joined by phosphodiester
linkages between the sugar of one nucleotide and
the phosphate of the next
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Macromolecules
Nucleic Acids