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Macromolecules Notes:
KEY WORDS/
QUESTIONS
General
Vocabulary:
Ch. 3
NOTES
Monomers: subunits that make up larger molecules.
“Parts that make up the whole.”
Polymers: a bunch of monomers all hooked together.
whole thing!
The
Examples:
1. Legos vs. Legoland
2. Bono vs. U2
3. A cinderblock vs. Hamilton High School
Dehydration Synthesis:
 AKA. Condensation reaction
 Process used to create polymers from the monomers.
 Used in anabolic reactions in the body (Reactions
that BUILD molecules.)
 Water is formed during the process. Why? b/c in
order to hook subunits together, they need to be
able to share electrons. If there are no electrons
to be shared, they won’t/don’t need to form a bond.
So...
 ...by removing an -H from one subunit and an –OH
from the other subunit, you have freed up electrons
that will now bond together to form the covalent
links that connect the monomers. The H and OH form
water.
 In the body these reactions are carried out by
enzymes known generally as POLYMERASES.
Hydrolysis:
 Process used to release monomers from the larger
polymer.
 Used in catabolic reactions in the body (Reactions
that BREAK DOWN molecules.)
 Water is used during the process. Why? b/c now you
have to break up one or more of the covalent links.
This leaves unhappy atoms with electrons that need
to be shared. So...
 ...water breaks up into –H and –OH and attaches to
make each side happy.
 In the body these reactions are carried out by
enzymes known generally as HYDROLASES.
Polymerization: process that creates polymers from
monomer subunits.
Macromolecules: organic molecules found in the body can
be classified as one of four things: proteins, nucleic
acids, carbohydrates and lipids. These are known as
macromolecules because they can be very large. These are
the “bricks and mortar” of our bodies...they make up the
cells and everything in them.
CARBOHYDRATES
Structure:
Types:
How can you tell carbohydrates apart from other
molecules?
 Only made of carbon, hydrogen and oxygen
 If given the formula: characteristic 1:2:1 ratio
 If given the name: most end with “-ose”
 If given the structure: look for the hexagon
shape...but then double check by looking for the
ratios. If not listed, each corner of the hexagon
is a carbon. Sometimes they aren’t always shown.
Monomer: simple sugar/monosaccharide
Polymer: polysaccharide
A. Monosaccharide: aka simple carbohydrate
Ex. Glucose, fructose, galactose
Interesting notes:
 All the examples listed above have the same
molecular formula. So how are they different? The
atoms are hooked together differently. These are
known as ISOMERS.
B.
C.
Testing for Carbs
Disaccharides: aka simple carbohydrate
Ex. Sucrose, maltose, lactose
Polysaccharides: aka complex carbohydrate
Ex. Cellulose, glycogen, chitin, starch
Interesting:
 All of the examples listed above are polymers of
glucose! So if they are all made of only glucose
how are they different?
 They differ in the way the glucose molecules are
attached. Cellulose and chitin are STRUCTURAL
polymers made with one type of glucose. Glycogen
and starch are ENERGY polymers made with the other
form of starch.
 Who cares? Cellulose and chitin are used in plants
and animals respectively for constructing cell walls
and exoskeletons. We (plants and animals) don’t
have the enzymes that recognize how the glucose
molecules are hooked together in this form...so we
don’t digest these forms! Good thing...if plants
had the enzyme they would have to find something
else to build their cell walls out of.
1. Iodine Test: Indicates the presence of starch.
 A positive test turns purple.
Macromolecules Notes:
Ch. 3
2. Benedicts Test: Indicates the presence of
monosaccharides.
 A positive test turns orangy.
LIPIDS
Structure:
How can you tell Lipids apart from other molecules?
 Made of carbon, hydrogen, oxygen and other
elements...typically phosphorous and nitrogen
 If given the formula: no characteristic ratio
 If given the name: no fancy way to tell. Sorry!
 If given the structure:
since there are three
classes of lipids, they each have a recognizable
shape: (See under “types” below)
Monomer:
Polymer:
Types:
Fatty Acids
Three exist: a. Triglyceride
b. Phospholipids
c. Steroids (Cholesterol)
A. Triglycerides:
 Made by attaching the glycerol head to the three
fatty acid tails. (Known as triglycerides)

 The fatty acid tails can be saturated or unsaturated
depending on the presence or absence of double
bonds.
 This molecule is entirely hydrophobic!
 Who cares? Unsaturated fats are liquid at room
temperature since they can’t pack tightly. Hence,
easier for the body to digest and don’t build up in
the blood stream. Saturated fats are solid at room
temp, can pack tightly together, so makes it harder
for the body to
digest.
 Typical Structure:
 Tails can be all
saturated, all
unsaturated or a
combination.
B.
Phospholipids:
 Made by taking off one
of the fatty acid
tails and replacing it with a molecule known as a
“phosphate group”
 By adding this group, you have now made a portion of
the molecule hydrophobic (the tails) and a portion


C.
is now hydrophilic (the head)
So what? You can now use this molecule as a type of
sack! When dropped into water, they
form spheres with the heads facing
the water and the tails in the
middle. You can put stuff inside
them!
Typical Structure:
Steroids:
 Made by combining tons of fatty
acids into rings.
 Characterized by looking for the
fused rings: (Don’t worry about the
numbers!)
Testing for
Lipids:
1. Emulsification Test: forms two layers when heated
in water and subsequently having ethanol poured in
2. Brown Paper Bag Test
3. Sudan IV Test: Turns red in the presence of a fat
Proteins
Structure:
How can you tell proteins apart from other molecules?
 Made of carbon, hydrogen, oxygen, sulfur, etc.
 If given the formula: no characteristic ratio
 If given the name: most end with “-in”
 If given the structure: look for the N – C – C (See
below)
Monomer: amino
acid
Key parts to
the amino acid:
Levels of
Organization:
Polymer:
protein or
polypeptide
(named because
the covalent
bond that links
the monomers is
known as a
peptide bond.)
Show how they bond together and you can tell how many AA
you have by looking at the # of NCC-s in a chain.
When proteins are made in living organisms they are QUITE
LARGE! A typical protein has about 50, 000 amino acids.
So they conserve space within the cell, they are packed
tightly. We will talk about how this happens later, but
for now, these are the levels of protein packaging:
Macromolecules Notes:
Ch. 3
1. Primary Structure: a simple chain of monomers. The
order the amino acids line up is dictated by the DNA
code.
2. Secondary Structure: the chain starts to coil (AKA
alpha helices) (like a telephone cord) and other parts of
the chain will accordion fold (AKA beta-pleated sheets)
KEY: They maintain their shape because parts of the
backbone forms hydrogen bonds (N from one amino group on
one amino acid bond to the O in the carboxyl group of
another aa)
3. Tertiary Structure: the coils and pleats now start
folding in on each other! KEY: The shape is maintained
by bonding at the R group level! Important here is to
know whether the amino acids are hydrophobic or
hydrophilic...the hydrophobic ones will cause the protein
to bend (during folding) away from water. The
hydrophilic won’t be bothered in the presence of water.
 All proteins are at least at this stage.
o Examples: keratin, antibodies, collagen
 All enzymes are at this stage. (Few exceptions)
4. Quaternary Structure: two proteins at the tertiary
stage have combined.
 Example: hemoglobin
Testing for
Proteins:
1. Buiret’s Test:
there!
turns a pretty purple if proteins are
Nucleic Acids
Structure:
Testing for
Nucleic Acids:
Monomer: nucleotides
Cool song: (Sung to Row, Row, Row Your Boat)
“We love DNA, made of nucleotides
Sugar, phosphate and a base bonded down one side.
Adenine and thymine make a lovely pair.
Cytosine without guanine would be oh so bare...OH”
Polymer: DNA or RNA
Don’t worry about!