Download Macromolecules

“Macromolecules
of Life”
ppt adapted from cmassengale
1
Organic Compounds
• Compounds that contain CARBON
are called organic.
• Macromolecules are large molecules.
• Organic Macromolecules
has C-C bonds
large molecules
2
Organic Compounds
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)
3
Organic Compounds
Carbon (C)
• What does sharing electrons with other
atoms, in four covalent bonds mean?
• Each carbon acts as an ‘intersection’
with 4 different branch points
• Creates endless variety of (organic)
carbon molecules
Vary in length
4
Diversity of Carbon-Based Molecules
Different location of double bonds
Rings
Unbranched or
branched
Macromolecules of Life
• Large organic molecules.
• Also called POLYMERS.
• Made up of smaller “building blocks”
called MONOMERS.
• Biological macromolecules
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids (DNA and RNA)
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Carbohydrates
“How Sweet it is”
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• SIZE
Carbohydrates
– small to large
• Types
A. monosaccharide (sugars)
B. disaccharide (sugars)
glucose
glucose
glucose
C. polysaccharide (starches)
glucose
glucose
glucose
glucose
glucose
glucose
glucose
cellulose
glucose
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Carbohydrates
• Monomer = sugar = “saccharide”
• Structure:
– Small (simple) sugar molecules
• Examples?
– Monosaccharides
» glucose, fructose
» galactose, deoxyribose
– Disaccharides
»Sucrose (glucose+fructose)
»Lactose (glucose+galactose)
»Maltose (glucose+glucose)
Carbohydrates
• Monomer = “saccharide”
• Structure:
– Large molecules
– Long chain of many single sugar units
hooked together
• Examples?
– Polysaccharides
» Starches…(Pasta, bread, potatoes)
»Cellulose … (lettuce, corn) provides
structure for plant cell walls
»Glycogen … (stored in liver, muscle cells break
down glycogen to release glucose when needed for
energy)
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Carbohydrate Function
• Functions
– Main source of energy for living things
• gasoline for cells (ATP)
– Monosaccharides = immediate E
– Polysaccharides = longer term E
– Plants store carbs as cellulose—gives
their cells strength
– Animals store carbs as glycogen
Lipids
“Greasy Molecules”
copyright cmassengale
12
Lipids
• Hydrophobic= water hating
• Hydrophillic= water loving
• Lipids =general term for compounds
which are not soluble in water.
• Lipids are soluble in other solvents.
13
Lipids
• Examples:
1. Fats – from animals
(butter,lard,margarine)
2. Oils-from plants
3.
4.
5.
6.
(canola oil, olive oil, corn oil)
Phospholipids (cell membranes)
Waxes (bees wax, ear wax)
Steroid hormones
Triglycerides
copyright cmassengale
14
Lipids
Six functions of lipids:
1.“stores the most energy”
Long term energy storage
2. Protection against heat loss
(insulation)
3. Protection against physical shock
(cushioning)
4. Protection against water loss
(hydrophobic)
5. Chemical messengers (hormones)
6. Major component of membranes
(phospholipids)
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Lipids
Technically called? Triglycerides
Composition:(1) glycerol and (3) fatty acids.
H
O
saturated 
H-C----O C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
saturated 
H-C----O C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
H-C----O C-CH -CH -CH -CH
2
2
2
unsaturated 
Fatty
Acids
H
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Fatty Acids
Two kinds of fatty acids you may see on food labels:
1.
Saturated fatty acids: no double bonds
()
solids at room temperature
saturated
2.
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
Unsaturated fatty acids: double bonds ()
liquids at
O
C-CH2-CH2-CH2-CH
room temperature
unsaturated
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Proteins
“Amazing Variety”
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Proteins (Polypeptides)
• Amino acids – building blocks – monomer
– (20 different kinds of aa) bonded together by peptide
bonds (polypeptides).
– Each a.a. made of….
• Central CARBON bonded to…
– Amino group (NH2)
– Carboxyl Group (COOH)
– Hydrogen
– “R” group
Amino
group
Carboxyl
group
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Examples of 2 different amino acids
and their side groups
copyright cmassengale
20
Proteins (Polypeptides)
Six functions of proteins:
1.Immune/Defense: Kill invaders (Antibodies)
2.Transport: Blood (hemoglobin),
Cell membrane proteins
3.Regulatory: hormones
4.Movement: muscles (Actin,Myosin)
5.Structural: Hair,horns,feathers (Keratin)
Skin (Collagen).
Bones,Tendons, Ligaments,
Cartilage (Connective Fibers)
6.Regulatory: help control cellular reactions
(Enzymes…-ase)
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Proteins (Polypeptides)
Four levels of protein structure:
A.Primary Structure
B. Secondary Structure
C. Tertiary Structure
D.Quaternary Structure
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Primary Structure
• Amino Acids linked (bonded) in a
STRAIGHT CHAIN
Amino Acids (aa)
aa1
aa2
aa3
aa4
aa5
aa6
Peptide Bonds
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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
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Tertiary Structure
• Secondary structures bent and folded
into a more complex 3-D arrangement
of linked polypeptides
• Bonds: H-bonds, ionic, disulfide
bridges (S-S)
• Call a “subunit”.
Alpha Helix
Beta Pleated Sheet
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Quaternary Structure
• Composed of 2 or more
“subunits”
• Globular in shape
• Form in Aqueous environments
• Example: enzymes (hemoglobin)
subunits
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Protein Structure - Quiz
copyright cmassengale
27
Nucleic
Acids
copyright cmassengale
28
Nucleic acids
• Two types:
a. Deoxyribonucleic acid (DNAdouble helix)
b. Ribonucleic acid (RNA-single
strand)
• Nucleic acids are composed of long
chains of nucleotides…building
blocks…monomer
copyright cmassengale
29
Nucleic acids
• Nucleotides include:
– phosphate group
– pentose sugar (5-carbon)
– nitrogenous bases:
DNA
adenine (A)
thymine (T)
cytosine (C)
guanine (G)
RNA
adenine (A)
uracil (U)
cytosine (C)
guanine (G)
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Nucleotide
Phosphate
Group
O
O=P-O
O
Nitrogen
Base
(A, G, C, T or U)
5
CH2
O
C4
Sugar
(deoxyribose) C1
C3
C2
N
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5
DNA
double
helix
O
3
3
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
copyright cmassengale
5
P
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DNA- Gene for Baldness
Build a DNA molecule
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