Transcript Biomacromolecules ppt

Bio-Macromolecules
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Organic Compounds
• Compounds that contain CARBON
are called organic.
• Macromolecules are large organic
molecules.
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Carbon (C)
• Carbon has 4 electrons in outer
shell.
• Carbon can form covalent bonds
with as many as 4 other atoms
(elements).
• Usually with C, H, O or N.
• Example:
CH4(methane)
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BIO-Macromolecules
• Large organic molecules.
• Also called POLYMERS.
• Made up of smaller “building blocks”
called MONOMERS.
• Examples:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids (DNA and RNA)
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Carbohydrates
(CH2O)n
CHO in 1:2:1 ratio.
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Carbohydrates
• 3 forms: Small sugar molecules
to large sugar molecules.
1. monosaccharide
2. disaccharide
3. polysaccharide
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Carbohydrates
Monosaccharide: one sugar unit
Examples
(3 most common)1.Glucose
glucose
2,Deoxyribose
3. Ribose
(C6H12O6)
and fructose galactose
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Carbohydrates
Disaccharide: two sugars unit
Examples:
– Sucrose
(glucose+fructose)sugar cane
– Lactose (glucose+galactose)milk
– Maltose (glucose+glucose)malt
glucose
glucose
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Carbohydrates
The function of carbohydrate is to store short(glucose) and long
term(starch) energy supply; structural function of cellulose.
Polysaccharide: many sugar units of
glucose
Examples:starch(plants) (bread, potatoes, wheat,corn)
glycogen(animals) (liver, muscle)
cellulose(plants) (lettuce, corn, wood, leaf etc)
glucose
glucose
glucose
glucose
glucose
glucose
glucose
cellulose
glucose
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Carbohydrates
Parallele lines allow for fiber formation:
which give structural strength
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Lipids
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Lipids
• General term for compounds which are non-polar and
not soluble in water.
• Lipids are soluble in hydrophobic solvents
• Lipids have more bonds(more energy)
than carbohydrates Remember: “ Lipids store the most
energy”. Long term storage of energy.
• Examples:
1. Fats
2. Phospholipids
3. Oils
4. Waxes
5. Steroid hormones Estrogen testosteron (Cholesterol)
6. Triglycerides
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Lipids
Six functions of lipids:
1. Long term energy storage
2. Protection against heat loss
(insulation)
3. Protection against physical shock
4. Protection against water loss
5. Chemical messengers (hormones)
6. Major component of membranes
(phospholipids)
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Lipids
Triglycerides (most lipids)
Are composed of 1 glycerol and 3
fatty acids.
H
H-C----O
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
H-C----O C-CH -CH -CH -CH -CH -CH -CH -CH -CH -CH
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2
2
2
2
2
2
2
2
3
O
H-C----O C-CH -CH -CH -CH
2
2
2
H
glycerol
3 fatty acids
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Phospholipids
Major building block of the cell membrane
Soluble in water
Hydrophilic head
Insoluble in water
Hydrophobic tails
Fatty Acids
There are two kinds of fatty acids you may see these on food labels:
1. Saturated fatty acids: no double bonds health , they are as
straight chains , thus are usually solid at room Temp (bad fat for
your health)
-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
2.Unsaturated fatty acids: Have double bonds, are bent in shape,
thus are liquids at room Temp. (good fat : Olive oil, salmon and
sardine oil, duck meat oil)
O
unsaturated C-CH2-CH2-CH2-CH
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Proteins
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Proteins (Polypeptides)
• Amino acids (20 different kinds of aa) bonded
together by peptide bonds (polypeptides).
• Six functions of proteins:
1. Storage:
albumin (egg white)
2. Transport: hemoglobin
3. Regulatory: hormones(insulin)
4. Movement: muscles
5. Structural: membranes, hair, nails,collagen
6. Enzymes: Catalyst to cellular reactions.
Enzymes are involve in metabolism
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Proteins (Polypeptides)
Four levels of protein structure:
A.Primary Structure
B. Secondary Structure
C. Tertiary Structure
D.Quaternary Structure
These protein’s structures are very sensitive to
temperature (those structures depend on hydrogen
bonds : albumin of egg white hardens with boiling
water) and PH (Amino acid ionic charges: casein of
milk curdles with acid of lemon juice)
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Example # 1: Collagen and Keratin
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Primary Structure
Amino acids (monomers) bonded together by peptide bonds that form straight
chains of Polymers(=polypeptide). Very large polypeptide = protein.
Metabolic proteins are Enzymes. Peptide bond is formed by the
Amino/Carboxyl sections of the Amino acid. The R group is responsible for
the Hydrogen and ionic bonds formed within the protein.
Amino Acids (aa)
aa1
aa2
aa3
aa4
aa5
aa6
Peptide Bonds
Amino acids only differ by their R group
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Secondary Structure
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Secondary Structure
• 3-dimensional folding arrangement of a
primary structure into coils and pleats
held together by hydrogen bonds.
• Two examples:
Alpha Helix
Beta Pleated Sheet
Hydrogen bonds( sensitive to temperature= denatured)
3 Example: Albumin in Egg white, Keratin in hair. Fever to
fight bacterial infection
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Tertiary Structure
• Secondary structures bent and folded into a
more complex 3-D arrangement of linked
polypeptides
• Bonds: Hydrogen-bonds, ionic, disulfide
bridges (S-S)
• Called a “subunit”.
This subunit is made of
3 chains of polypeptide
Alpha Helix
Beta Pleated Sheet
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Quaternary Structure
Example # 2
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Quaternary Structure
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Quaternary Structure
• Effect of temperature and PH
On four different Enzymes(proteins) (A,B,X,Y)
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Nucleic
Acids
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Nucleic acids
• Two types:
a. Deoxyribonucleic acid (DNAdouble helix)
b. Ribonucleic acid (RNA-single
strand)
• Nucleic acids are composed of long
chains of nucleotides
• The function of nucleic acids is to
contain and transfer genetic
information.
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Nucleic acids
• Nucleotides include:
phosphate group
pentose sugar (5-carbon)
nitrogenous bases:
adenine (A)
thymine (T) DNA only
uracil (U) RNA only
cytosine (C)
guanine (G)
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A Nucleotide
Phosphate
Group
O
O=P-O
O
5
CH2
O
N
C1
C4
Nitrogenous base
(A, G, C,T or U)
Sugar
(deoxyribose)
C3
C2
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Nitrogenous bases
Purines
Adenine
Guanine
Pyrimidines
Cytosine
Thymine
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DNA
double
helix
O
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Hydrogen bonds
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O
P
5
O
C
G
1
P
5
3
2
4
4
2
3
1
P
T
5
A
P
3
O
O
P
5
O
3
5
P
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DNA - double helix
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