Download Macromolecules - Georgetown ISD

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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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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Question:
How Are
Macromolecules
Formed?
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Answer: Dehydration Synthesis
• Also called “condensation reaction”
• Forms polymers by combining
monomers by “removing water”.
HO
H
HO
H
H2O
HO
H
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Question:
How are
Macromolecules
separated or
digested?
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Answer: Hydrolysis
• Separates monomers by “adding
water”
HO
H
H2O
HO
H
HO
H
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Carbohydrates
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• Characteristics of Carbohydrates
• “Carbs” consist of carbon, hydrogen, &
oxygen atoms in a 1:2:1 ratio
• Energy containing molecules
• Some provide structure
• The MONOMER of a carbohydrate is
a monosaccharide (CH2O)n
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Carbohydrates
• Carbs range in size from small, simple
sugar molecules to large, complex
molecules that result when many simple
sugars are bonded together.
Three categories of carbohydrate:
A. monosaccharide
B. disaccharide
C. polysaccharide
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Carbohydrates
Monosaccharides: Single “loop”, simple
sugars. These are the MONOMER of
all carbohydrates.
Examples:
glucose
glucose (C6H12O6)
deoxyribose
ribose
Fructose
Galactose
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Carbohydrates
Disaccharide: two sugar unit
Examples:
– Sucrose (glucose+fructose)
– Lactose (glucose+galactose)
– Maltose (glucose+glucose)
glucose
glucose
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Carbohydrates
Polysaccharide: many sugar units
Examples: starch (bread, potatoes)
glycogen (beef muscle)
cellulose (lettuce, corn)
glucose
glucose
glucose
glucose
cellulose
glucose
glucose
glucose
glucose
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Important Polysaccharides:
Starch
• Consists of glucose
subunits
• Plant energy storage
molecule
• Glycogen is a very
similar molecule in
animals.
• Starch and glycogen
can be digested by
animals.
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Important Polysaccharides:
Cellulose
• Composed of
glucose subunits
• Structural
component in plants
• Cannot be digested
by humans
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Lipids
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Lipids
• General term for compounds
which are not soluble in water.
They are hydrophobic.
• Remember: “store the most
energy”
• Composed of Carbon, Hydrogen, and Oxygen
• Greater than 2:1 ratio of H:O
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Lipids
Triglycerides:
The MONOMER of lipids:
made of 1 glycerol and 3
fatty acids.
H
O
H-C----O C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
H-C----O C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
fatty acids
H-C----O C-CH -CH -CH -CH
2
2
2
H
glycerol
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Lipids
• Examples of lipids:
a. fats
b. phospholipids
c. oils
d. waxes
e. steroid hormones
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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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Fatty Acids
There are two kinds of fatty acids you may see
these on food labels:
1. Saturated fatty acids: no double bonds
(bad ~ solid
at room temperature)
O
saturated C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
2. Unsaturated fatty acids: double bonds
(good ~ liquidOat room temperature)
unsaturated C-CH2-CH2-CH2-CH
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Proteins
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Proteins (Polypeptides)
•
THE MONOMERS of proteins are
acids.
Amino
• There are 20 different kinds of amino
acids. Depending on what order they bond
in, different types of proteins are made.
• The amino acids are bonded together by
peptide bonds. So, sometimes proteins are
called polypeptide chains.
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Proteins
• Six functions of
1. Storage:
2. Transport:
3. Regulatory:
4. Movement:
5. Structural:
6. Enzymes:
proteins:
albumin (egg white)
hemoglobin
hormones
muscles
hair, nails
cellular reactions
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Primary Structure
Amino acids bonded together
by peptide bonds (straight
chains)
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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Nucleic
Acids
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Nucleic acids
• The MONOMER of a Nucleic acid is
a NUCLEOTIDE.
• Nucleotides include:
A phosphate group
A pentose sugar (5-carbon)
A nitrogen bases:
adenine (A)
thymine (T) DNA only
uracil (U) RNA only
cytosine (C)
guanine (G)
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Nucleotide
Phosphate
Group
O
O=P-O
O
5
CH2
O
N
C1
C4
Nitrogenous base
(A, G, C, or T)
Sugar
(deoxyribose)
C3
C2
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Nucleic acids
• There are two types of nucleic acids:
a. Deoxyribonucleic acid (DNA)-
Gives hereditary information to
chromosomes, which is then passed
from parent to offspring.
b. Ribonucleic acid (RNA)- Directs
the amino-acid sequence for making
certain proteins.
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DNA vs RNA
• DNA
1- Deoxyribose sugar
2- Nitrogen Bases: Adenine, Thymine, Cytosine,
Guanine
3- Double-stranded helix arrangement
• RNA
1- Ribose sugar
2- Nitrogen Bases: Adenine, Uracil, Cytosine,
Guanine
3- Single stranded
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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
5
P
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