Organic Compounds
Essential Questions:
What is “Organic?”
What are the 4 major Organic Compounds?
How are they made?
What are they used for?
What do we already know?
Aristotle: Spontaneous Generation
Francesco Redi: Covered meat  No maggots.
Uncovered meat  maggots.
First strike against
Spontaneous Generation
Second strike BUT
Boiled
broth
open

growth.
Lazzaro Spallanzani:
Boiled broth sealed  no growth. Argued he boiled “life
force”
Louis Pasteur: Boiled broth, curvy neck no growth.
Boiled broth, curvy neck removed  growth.
He believed that energy from lightning and the
Alexander Oparin: sun can spark chemical reactions to create
macromolecules like proteins.
Spontaneous
Generation
Disproved!
Miller and Urey: Created the basic building blocks of life under conditions that
mimicked the conditions of early earth.
Sidney Fox: Created and studied coacervates.
Organic Molecules make up all organisms
What does “Organic” Mean?
In Biology, organic means “relating to organisms.”
NOT food grown without the use of pesticides,
antibiotics, or other industrial chemicals.
What do all organic compounds contain?
All organic molecules contain
covalently bonded Carbon.
What does “Organic” Mean?
Carbon cycles through all living things through the processes of photosynthesis, cellular
respiration, death, and decomposition.
We’ll talk more about the Carbon Cycle in a few weeks!
Why Carbon is so Awesome...
How many bonds/shared electrons can a Carbon atom make?
• Carbon can bond to other carbon atoms, which gives carbon the
ability to form chains that are almost unlimited in length.
• These carbon-carbon bonds can be single, double, or triple.
• The chains can be straight, branched, or even ring-shaped.
• Therefore, carbon is unique in that it can form millions of
different large and complex structures.
How are the Four Organic Macromolecules Formed?
Polymerization: small units (monomers) are joined together to form
large units (polymers.)
Dehydration synthesis: joins molecules by
removing a molecule of water.
Monomer +
monomer =
Hydrolysis: breaks apart molecules by adding
water (the opposite process)
What are the four organic molecules?
Carbohydrates
Proteins
We get
from food!
Lipids
Nucleic Acids
Resides (stays)
in our cells!
What is in a cheeseburger?
Nutrition Facts (Big ‘N
Tasty at McDonalds):
Total Fat: 29 grams
Saturated Fat: 9 grams
Carbohydrates: 41
grams
Protein: 24 grams
Carbohydrates
Which part of the cheeseburger has
the most carbohydrates?
Carbohydrates
• Composed of Carbon, Hydrogen and Oxygen in a 1:2:1 Ratio.
• Used for short term energy storage (quick energy!) and structural
support
• Ending “-ose” = sugar
Glucose
Cellulose
How many sugars?
Examples
1 sugar
Monosaccharide Monomer
Plants: glucose, fructose
Animals: galactose
(milk)
2 sugars
Disaccharide
Polymer
Plants: sucrose, maltose
Animals: lactose (milk)
3+ sugars
Polysaccharide
Polymer
Plants: starch, cellulose
Animals: glycogen
Monomer + monomer =
One sugar =
Two sugars =
Three or more sugars =
Why Carbohydrates?
• Many animals store extra sugar as glycogen.
– Glycogen stored in your muscles supplies energy for
movement.
– Glycogen stored in your liver is released when the
glucose (sugar) in your blood runs low.
• Recall: What is this an example of?
– Homeostasis!
• Plants store excess sugar as starch.
• Plants also make cellulose, a strong, rigid fiber
used for support.
Starch, cellulose and glycogen are all… Polysaccharides!
What other part of the Big N’ Tasty
is composed of carbohydrates?
Cellulose!
Which part of the cheeseburger
is the best source of protein?
Proteins
Proteins are present in
every cell, tissue and
organ in our bodies.
These proteins are
constantly being broken
down and replaced.
Composed of Carbon,
Hydrogen, Oxygen,
Nitrogen, and Sulfur
Provide structure for:
cells, bones, muscles, tissues, organs, hormones…most everything in the
body!
Special Function: Proteins are responsible for cell metabolism (via
enzymes)
Proteins
The protein in the food we
eat is digested (broken
down) into amino acids that
are later used to build and
replace other proteins in our
bodies.
Monomers = amino
acids
Polymers = proteins
The monomers in an amino acid are held together
by peptide bonds.
Proteins can be destroyed by extreme heat (fever)
= denature
When the amino acids
join, they form a
polymer called a
polypeptide.
Protein Structure
Amino acids are the building blocks
of proteins.
There are 20 essential amino acids.
All amino acids have the same Amino group and carboxyl
groups, but each amino acid has its own unique R- group. Only
20 amino acids can combine in different arrangements to
form all of the many different kinds of proteins in our bodies!
Shape is very important; if a protein is not the right shape, it
will not work or only have partial function!
Which part of the cheeseburger
is a source of fat?
What is fat?
• Fats are a type of lipid.
• Lipids are hydrophobic
(water-fearing) organic
molecule including fats, oils,
waxes, phospholipids and
steroids.
Lipids
Long chains with lots of Carbon and
Hydrogen (long chains), but little or
no oxygen
Monomers: 1 glycerol & 3 fatty acid chains
Polymer: lipid
If we know that lipids (fat) are hydrophobic
and take a long time to break down,
what could it be useful for??
–
–
–
–
–
–
Long term energy storage
Protection
Insulation
Waterproofing
Cell Membranes
Chemical Messengers
(steroids)
Lipids come in two flavors…
Saturated: Single Bonds
•
•
•
•
Unsaturated: Double Bonds
Animal Fats
Harder to digest
Solids at room temperature
Holds as many Hydrogen atoms as possible
•
•
•
•
Vegetable Oils
Easier to digest
Liquids at room Temperature
Does not hold as many hydrogen
atoms as possible
Your Turn! Make a quick hypothesis to why Unsaturated
Fats are easier to break down (thus healthier for you)
than Saturated Fats!
It is easier for your body to break double bonds than
single bonds due to the number of electrons. Aka, it’s
easier to steal 1 electron from Carbon when it is sharing
two versus just that one! (Like borrowing money!)
Common Misconceptions:
Lipids – Good & Bad Cholesterol
You’ll be amazed at what you find online about the different types of
cholesterol! You should check it out!
What is a nucleic acid?
DNA:
Deoxyribonucleic
Acid
How do nucleic acids relate to
the cheeseburger?
DNA
Is transcribed into RNA,
which is then translated
into proteins.
DNA  RNA  Proteins!
Nucleic Acids
• Carbon, Hydrogen, Oxygen,
Nitrogen, and two
Phosphorus atoms
arranged in 3 groups
(monomers)
• Used for storing and
transmitting cellular
information in a code called
DNA or RNA.
Nucleic Acids
• Monomer:
Nucleotide
Nitrogen Base
– Nitrogen Base
• A, G, C, T or U
Phosphate group
– 5-Carbon Simple Sugar
• Deoxyribose (DNA)
• Ribose (RNA)
– Phosphate group
• Polymer – DNA or RNA
Simple Sugar
Organic molecules are the
building blocks of life
They are broken down into monomers,
then rebuilt into polymers,
then broken down again, then rebuilt again!
And so life goes on…
Your turn!
What kind of macromolecules
did you/will you eat today?