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
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.
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
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: Function
• Build and repair muscle
and tissues
– “No pain, no gain!”
• Enzymes- proteins that speed up chemical
reactions
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.
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
• DNA, RNA
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!).
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