Macromolecules
Life: Small Picture to Big Picture
Macromolecules
What are Macromolecules?
•  Cells and their organelles are made up of
smaller building blocks called
macromolecules.
•  There are 4 basic types of
macromolecules. They are:
–  Lipids
–  Proteins
–  Carbohydrates
–  Nucleic Acids
Monomers & Polymers
•  Macromolecules are actually made up of
even smaller subunits. Each subunit of a
macromolecule is called a monomer.
•  The macromolecules themselves are
called polymers, because they are made
up of many of these subunits.
Monomer: one basic unit or subunit
Polymer: a chain of many basic units
What you need to know:
•  Names of the 4 macromolecules
•  Structure- monomers and polymers of
each
•  Function- what are they used for?
•  Food sources- what foods will you find
these in?
•  Indicator Tests- what tests do we use to
find out if a food contains them?
Lipids
Lipids: Structure
•  Lipids are made up of…
–  Monomer (basic unit): fatty acids
–  Polymer (chain of units): lipids
•  Specific examples: triglycerides, phospholipids
Lipids: Structure*
Properties of Lipids
caused by:
•  Saturated vs.
Unsaturated fatty
acids
•  Polar head and
nonpolar tail regions
–  Hydrophilic and
hydrophobic regions
Lipids: Function
•  Make up the cell membrane, providing cell
structure
•  Provide insulation (fat keeps body warm)
•  Long-term energy storage
Lipids: Food Sources
•  As you might have guessed, fatty foods
contain lipids.
•  Lipids are found in meat and fish, oils,
avacados, eggs & nuts.
Lipids: Indicator Test
•  Paper Bag Test:
–  Smear substance onto paper bag
–  If see-thru, it contains lipids
Lipids Indicator Test
•  Sudan III test
•  Sudan III is a solid that will
dissolve in fats.
•  Sudan III is a brownish-red
powder an will turn bright
red when mixed with lipids
•  Sudan III will not change
color or appearance when
mixed with other
macromolecules
Proteins
Proteins: Function
•  The function of a
•  Enzyme Proteins
protein depends on •  Structural Proteins
its structure.
•  Contractile
Proteins
•  Proteins have
•  Defensive Proteins
many functions in
•  Signal Proteins
living things
•  Transport Proteins
•  Storage Proteins
Proteins: Structure
•  Proteins are made up of…
–  Monomer (basic unit):
amino acids
•  20 different kinds!*
–  Polymer (chain of units): protein
•  More specifically- polypeptides
dipeptide
Amino acids
linked by
peptide
bonds
H
Proteins: Structure*
20 Amino
Acids:
Some of these
are polar &
hydrophilic,
others are nonpolar and
hydrophobic.
Proteins can
contain both
kinds.
Proteins: Structure
•  Proteins have complex
structures. The shape
of a protein determines
its function!
•  The levels of protein
structure are:
–  Primary structure:
polypeptide chain
–  Secondary structure:
polypeptides in coils or
sheets
–  Tertiary structure: coils or
sheets form a tangle
–  Quaternary structure:
more than one tangle
combine to make a very
complex protein!
Proteins: Enzymes
•  Enzymes- proteins that speed up chemical
reactions
•  Enzyme activity Lpscience.fatcow.com
Proteins: Food Sources
•  Proteins are found in meat, fish,
legumes, nuts, milk, eggs, grains and
soy products.
•  There are 6 amino acids that our bodies
cannot make- we can only get these from
food.
Proteins: Indicator Test
•  Biuret’s Solution:
–  Turns from blue to purple if protein is present
Carbohydrates
Carbohydrates: Structure
•  Carbohydrates are made up of…
–  Monomer (basic unit): simple sugars (or
monosaccharides)
•  Ex.: glucose
–  Polymer (chain of units): complex
carbohydrates (or polysaccharides)
•  Ex.: starch, cellulose, chitin, glycogen
Disaccharide:
2 simple
sugars bonded
together
Carbohydrates: Function
•  Provide body with energy!
Complex carb (ex. Starch)
–  What should you eat before
playing the big game?
Candy bar or pasta?
•  Candy bar: contains
simple sugars, provides a
short burst of energy
•  Pasta: contains starch
which takes longer to
break down, provides
longer-lasting energy
–  *We can’t digest celluloseit is used as fiber, or
roughage instead.
Broken down to
disaccharides
Broken down further
•  Ex. : corn
Simple sugars (ex. Glucose)
Carbohydrates: Food Sources
•  Simple carbs (simple
sugars) are found in
most candy and
sweet drinks, fruit,
vegetables, and milk.
They are quickly
digested and give a
short burst of energy.
•  Complex carbs (like
starches) are found in
pasta, bread,
potatoes, legumes &
corn. They take
longer to digest, and
provide energy
longer.
Carbohydrates: Indicator Tests
•  Simple Sugars:
–  Benedict’s solution
–  Blue solution turns
orange/green/brown
•  Complex Carbs:
–  Lugol’s solution/
Iodine
–  Turns from orangered-brown to blackpurple
What is an indicator?
•  An “indicator” is a specific chemical
compound that reacts with certain
macromolecules.
•  Benedict’s solution reacts when glucose is
present (with the help of a little heat)
How??
•  Benedict Solution is light blue because it
contains copper sulfate.
•  When it is mixed and heated with a sugar, such
as glucose, which has electrons available to
donate, the copper will accept the electrons and
become reduced, which turns it brownishorange.
•  If glucose is not present, the copper will not be
reduced and the benedict’s solution will not
react and stay blue
•  http://youtu.be/J7glsbXAmdU
•  http://youtu.be/Lt7RCIfudYQ
Nucleic Acids
Nucleic Acids: Structure
•  Nucleic Acids are made up of…
–  Monomers (basic unit): nucleotides
–  Polymers (chain of units): DNA or RNA
Nucleic Acids: Function
•  Stores and carries genetic information
Nucleic Acids: Food Sources
•  We get nucleic acid components from
vitamins and minerals in our diet.
These in turn, come from fruits,
vegetables, grains, meats, & almost
anything else you can think of with
some nutritional value (no junk food!).
Nucleic Acids: Indicator Test
•  You will not be using an
indicator test for these but in
case you’re wondering…
•  Dische diphenylamine test
–  Turns from clear-light blue
to dark blue if nucleic acids
are present
Digestion & Reconstruction
•  When macromolecules are eaten, they are
digested and broken down into their
subunits (monomers).
–  Analogy: taking apart an old brick building
•  Inside the cells, these subunits are
reconstructed into the macromolecules we
need.
–  Analogy: using bricks to build a new building
Digestion Products
Macromolecule
eaten:
Carbohydrates
Broken down in stomach
to:
Simple sugars (i.e. glucose)
Lipids
Proteins
Fatty acids & glycerol
(glycerol further broken down
to glucose)
Amino acids
Nucleic Acids
Nucleotides