Biological
Macromolecules
& enzyme
Heba Al-Tamimi 
1
Macromolecules
 Examples:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids
 All of the above are polymers except
lipids
 Polymers : formed by joining one or more
building blocks called MONOMERS.
2
Dehydration Synthesis
• Polymers are formed by dehydration
synthesis that involves removal of
water.
HO
H
HO
H
H2O
HO
H
3
Hydrolysis
• Separates monomers by “adding
water”
HO
H
H2O
HO
H
HO
H
4
Carbohydrates
5
Carbohydrates: Structure
• Classfication
• Monosaccharides: simple sugars (monosaccharides)
• Ex.: glucose
– Polymer (chain of units): complex carbohydrates (or
polysaccharides)
• Ex.: starch, cellulose, chitin, glycogen
Disaccharide:
2 simple
sugars bonded
together
Carbohydrates
Monosaccharide: one sugar unit
Examples:
glucose (C6H12O6)
Fructose
Galactose
glucose
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Carbohydrates
Disaccharide: double sugar
Examples:
– Sucrose (glucose+fructose)
– Lactose (glucose+galactose)
– Maltose (glucose+glucose)
glucose
glucose
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Carbohydrates
Polysaccharides: polymers composed
of many sugar building blocks
Examples: starch
glycogen
cellulose
glucose
glucose
glucose
glucose
cellulose
glucose
glucose
glucose
glucose
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Carbohydrates: Indicator Tests
• Reducing sugars :
 Benedict’s test
is used as a simple test
for detecting reducing sugars
• Complex Sugars(Polysaccharides)
 Lugol’s test /Iodine
5-1 Benedict’s solution
-CooH
1-
+ Cu2O
+ CuSO4/0H
(Red –brown precipitate)
Maltose
2-
reducing
Glucose + Galucose
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Benedict’s solution
Sucrose
Non-reducing
3Glucose + Fructose
Lactose
4-
Non-reducing
Glucose + Galactose
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Benedict’s test
glucose
maltose sucrose
starch
H2 O
2cm
Benedict
1cm
solution
Fill 5 of test tubes to I cm with following solution:
{glucose, maltose, sucrose, starch & water}
Fill each of the test tube to the 3 cm mark with Benedict’s reagent
Place test tube in hot water bath (5 min)
Observe color change
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5-2 The iodine test(lugol’s)for
starch
• Detect the presence of starch
 Starch :glucose polymer
 Glycogen: glucose polymer
 Iodine potassium iodide, I2KI, interacts w coiled starch
and becomes bluish black color
So ,form is important
iodine test(lugol’s)
glucogen
glucose
sucrose
starch
H2 O
2 drop
Lugol’s
2cm
solution
Fill 5 of test tubes to I cm with following solution:
{glucose, sucrose, starch ,glucogen & water}
Add 2 drops of Iodine
Observe color change
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Negative Test
Positive Test
Proteins
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Proteins: Structure
• Proteins are made up of…
 Monomer (basic unit):
amino acids
• 20 different kinds!
Amino acids
linked by peptide
bonds
Proteins
 Ninhydrin test for amino acids (aas.)
aas. having free amino groups are readily
detected with ninhydrin -> purple or violet
 The Biuret test for polypeptide
The amino group in one aas. is linked to carboxyl
group on an adjacent aas. by a peptide bond
this band is the site of action for the Biuret test
for protein , Cu 2+must complex with at least four
to six peptide bounds to produce violet color
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5-3 Ninhydrin test for amino acid
albumin
glycogen
milk
a.a
H2 O
5 drop
ninhydrin
+ heat
2 cm
solution
Fill 5 of test tubes to I cm with following solution:
{albumin ,glycogen, milk ,a.a (glycine) & water}
Add drops of ninhydrin reagent
Place test tube in hot water bath (5 min)
Observe color change
@ sink Skin irritation
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The Biuret test for polypeptide
albumin
glycogen
milk
a.a
H2 O
2 cm
Biuret
2 cm
solution
Fill 5 of test tubes to 3 cm with following solution:
{albumin ,glycogen, milk ,a.a (glycine) & water}
Fill each test tube to the 4 cm with Biuret solution and mix
Observe color change
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5-4 The Biuret test for polypeptide
1% CuSO4 -> Cu2+ Complexes w at least 4-6 peptide
bonds and produces violet color
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Lipids
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Lipids: Structure
• Fat is constructed from 2 kinds of smaller
molecules :
1-glycerol
2-fatty acid
• Lipids are not soluble in water, but soluble
in organic solvents.
Lipids “demo”
5-6 Lipid Solubility test
Lipids are insoluble in polar solvent and
soluble in nonpolar solvent




fill 2 tubes to the 2 cm mark with corn oil
In First tube, add 5 ml of tap water
In second tube, add 5 ml of mineral oil
Detect solubility
 5-5 Sudan red for fat (book)
 Sudan red is a lipid soluble dye
• Add 10 drops of Sudan red to tube number 1 in
above experiment
• Observe color , where is the red color found?
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Nucleic Acids
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Nucleic Acids: Structure
• Nucleic Acids are made up of…
– Monomers (basic units): nucleotides
• Two types:
 Deoxyribonucleic acid (DNA-double helix)
 Ribonucleic acid (RNA-single strand)
5-9 Dische diphenylamine test
“demo”
• In this test ,acidic condition convert deoxyribose
to a molecule that binds with diphenylamine to
form a blue complex.





Number 3 test tube 1-3
Into tube 1,place10 drops of banana DNA
Into tube 2,place 10 drops of standard DNA
Into tube 3,place 10 drops of distilled water
Add 1 ml of diphenylamine regent
Banana
 Place in a boiling water bath for 10 min
 Transfer the tubes to ice
 Observe color change.
DNA
Standard
DNA
water
Enzymes…
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Enzyme
Substrate(s) +enzyme
Optimal
conditions
We will take 2 examples
1- casein (protein milk)+Rennin
2- catechol +catechol oxidase
product(s)
Optimal
condition
Optimal
condition
coagulation
benzoquinone
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Enzyme (Rennin)
• Rennin is found in the stomach of young
mammals
• The enzyme coagulate the casein ,a protein
found in milk
• Optimal condition
 pH = ~7 (neutral)
 Temperate = 37 C
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6-1 Effect of temperature on enzyme activity
Put 3 ml Rennin
Place at 100 C for 5 min
Place at 0 C
for 5 min
Place at 37 C for 5 min
“Accurate measures”
Add milk (2/3) full
,then incubate to
37 C for 15 min
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6-2 Effect of pH on enzyme activity
Put 3 ml Rennin
Add 3 ml HCl
Add 3 ml NaOH
Add 3 ml H2O
Add milk to each tube
(2/3) full ,then incubate
at 37 C for 15 min
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6-4 Enzyme (Catechol oxidase) “demo”
• Catechole oxidase is an enzyme that
turns bruised or cut fruits and
vegetables brown
• Catechol is a clear chemical ,when it
reacts with oxygen in presence of the
enzyme catechol oxidase ,it forms the
dark brown product ,benzoquinone
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Catechol oxidase “Demo”
• Prepare 3 test tubes using the following table
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Go To Work……
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