Organic
Chemistry
Organic Chemistry
• Organic molecules  contain at least Carbon
and Hydrogen
• Hydrocarbons  contain ONLY Carbon and
Hydrogen
• Inorganic molecules may have Carbon OR
Hydrogen, but not both!
Practice
• Identify the following molecules as:
– Organic, Inorganic, Hydrocarbon
CH4
C6H12O6
H20
CO2
C2H5OH
Why is carbon so nifty?
• Has 4 valence electrons, meaning it can form 4
covalent bonds!
• It can form single, double, even triple bonds!
Bonding Characteristics of Elements
• Different numbers of valence electrons 
each element will make different numbers of
covalent bonds
• Carbon  4
• Oxygen  2
• Nitrogen  3
What are cells made of? (cont)
• Mostly made of water
• Organic Macromolecules are the major
organic components of the cell
– Macro  Big
– Organic  Contains carbon and hydrogen
– Molecules  Bonded together
4 classes of Organic Macromolecules
• Carbohydrates
– Sugars, starches, plant fiber (cellulose)
• Lipids
– fats, oils, waxes
• Proteins
– Muscle tissue, enzymes
• Nucleic Acids
– DNA, RNA
BIG IDEAS
• The cells of organisms are ALL made of the
same 4 types of macromolecules. AT THE
CELLULAR LEVEL, LIFE IS PRETTY MUCH ALL
THE SAME!
• Organisms are constantly BUILDING UP and
BREAKING DOWN organic molecules
How to Build a Macromolecule
• Start with a small single molecule  MONOMER
• Linking many monomers together  POLYMER
Monomer
Polymer
Figure 2-27 Essential Cell Biology (© Garland Science 2010)
How we BUILD –UP and BREAK DOWN
• Building Up
– Use DEHYDRATION SYNTHESIS
• Dehydration – removing water
• Synthesis – Building - up
• Breaking Down
– Use HYDROLYSIS
• Hydro – water
• Lysis – splitting apart
Dehydration Synthesis
• Monomers are linked together by the removal
of an OH from one side and an H from another
to make WATER
Hydrolysis
• Opposite of Dehydration Synthesis
• Water molecule is put back in, which results in
polymers separating into monomers
Remember, this whole unit is going to focus on how we
BUILD UP and BREAK DOWN the four major building
blocks of macromolecules
Monomers
MONOSACCHARIDES
Figure 2-15 Essential Cell Biology (© Garland Science 2010)
Polymers
CARBOHYDRATES
Monomer of carbs: monosaccharide
- means “one sugar”
- these are the simple sugars (taste sweet!)
- made of C, H and O in a 1:2:1 ratio
Simple vs. Complex Carbs
Glucose (monosaccharide)
Starch (polysaccharide)
Types of Carbohydrates
• MONOSACCHARIDES
– ONE SUGAR
– Ex GLUCOSE, FRUCTOSE, GALACTOSE
• DISACCHARIDES
– TWO SUGARS
– EX LACTOSE (Dairy), SUCROSE (sugar in bowl)
• POLYSACCHARIDES – MANY SUGARS
– STARCH – storage in plants
– GLYCOGEN – storage in animals
– CELLULOSE – plant cell walls
Monosaccharides
• Called simple sugars (one unit)
– Three simple sugars are absorbed with no digestion
(meaning….?)
• glucose found syrup or honey
• fructose found in fruit - sweetest
• galactose found in dairy products
ISOMERS!!!!!!!
Disaccharides
• Two monosaccharides are joined together to build
disaccharides
• sucrose (a sugar) can be produced by dehydration
synthesis of glucose and fructose.
• Lactose = Disaccharide formed by joining glucose and
galactose.
Polysaccharides
Long chains of monosaccharides!
• Glycogen (animal starch)
– Short term energy storage in
animals (fat is what we use
for long-term)
• Plant starch
– stores excess sugar
in a plant.
• Cellulose
– provides strength and rigidity
in plants
– We cannot digest!
Polysaccharides as Energy Storage
Molecules (cont.)
Polysaccharides as Energy Storage
Molecules (cont.)
Polysaccharides as Energy Storage
Molecules (cont.)
Polysaccharides and YOU!
• You eat starch from plants and break it down
into glucose (monosaccharide)
• Your cells take the glucose from your blood and
– A. Use it right away for cell energy
– B. Save it for later by linking them together into
large molecules of glycogen (pasta party anyone?)
• The other polysaccharide plants make,
cellulose, is NOT DIGESTABLE by you. So, it is
what we call dietary fiber……..hmmmm…..?
Cellulose and our ecosystem
• Plants = Structurally made of cellulose
• We (animals) cannot break it down when we
eat it
• So, what happens to all those leaves, grass
clippings, banana peels etc?
– DECOMPOSITION!
– BACTERIA AND FUNGI CAN BREAK DOWN PLANT
CELLULOSE
Lipids
• Lipids are a diverse group of macromolecules
that are insoluble in water.
• Fats and oils are well-known lipids used for
energy storage and other purposes.
• Phospholipids are components of the
membranes that surround cells.
• Steroids, which have a different structure from
most lipids, are used as hormones and for other
purposes.
Fats and Oils: Long-term Energy
Storage
• Fats and oils contain two subunits.
– Glycerol is a compound with three polar –OH groups.
– Fatty acids are long chain hydrocarbons.
• A fat or oil is formed when a dehydration
reaction adds fatty acids to the –OH groups of
glycerol and broken down by hydrolysis
reactions.
• Since three fatty acids are attached to a glycerol,
fats and oils are often called triglycerides.
Triglycerides (large lipid molecule)
• Composed of fatty acids
and glycerol
Building a triglyceride
Triglyceride formation animation
How would we break one down????
Fatty Acids
• Have a long hydrocarbon (carbon and hydrogen)
chain with a carboxyl group.
• Chains usually contain 16-18 carbons
• SATURATED VS. UNSATURATED
– SATURATED
• FATTY ACIDS HAVE ONLY SINGLE BONDS
• FORM STRAIGHT CHAINS – COMPACT AT
ROOM TEMP. (solid fats)
– UNSATURATED
• FA’S HAVE ONE OR MORE DOUBLE BONDS
•  KINK – LIQUID AT ROOM TEMP. (oils)
Polyunsaturated – More than one double
bond in the carbon chain.
Fatty Acids (unsaturated.)
Fatty Acids (saturated.)
Saturated vs. Unsaturated Fatty Acids
See your Lipids reading/questions for info on
these. You are responsible for structural
differences between each of the following and
the effect of those differences:
– Saturated
– Unsaturated (polyunsaturated)
– Hydrogenated
– Trans
LIPIDS:
FUNCTIONS
• LONG TERM ENERGY
STORAGE
– STORED IN ADIPOSE (fat)
TISSUE
– More energy per gram
than glycogen
– STRUCTURAL
• CELL MEMBRANES]
•
http://micro.magnet.fsu.edu/cells/plasmamembrane/images/plasmamembranefigure1.jpg
Fat vs. Carbs for energy storage?
Phospholipids: Membrane
Components
• Phospholipids
• Have a a polar, hydrophilic phosphate group
(instead of a third phosphate group.)
• Phospholipids can form bilayers that surround
cells. We will talk more about this in the next
unit!
Phospholipids: Membrane
Components (cont.)
Steroids:
- another type of
lipid
- four Fused Rings
- examples include
cholesterol and
certain hormones
PROTEINS
• IMPORTANCE!?!?!
• Some important functions of proteins are listed
below.
–
–
–
–
–
–
–
enzymes (chemical reactions)
hormones
storage (egg whites of birds, reptiles; seeds)
transport (hemoglobin)
contractile (muscle)
protective (antibodies)
membrane proteins (receptors, membrane transport,
antigens)
– structural
– toxins (botulism, diphtheria
Protein monomers  Amino Acids
• Twenty different amino acids are used to make
protein. Each has a carboxyl group (COOH) and an
amino group (NH2).
Amino Acids: Subunits of Proteins
(cont.)
Proteins
There are 20 different amino acids
- all have same amino end, carboxyl
end and central carbon
- EACH has a different R group
Amino acids are made of:
C, H, O, N, and S (in R group of some)
Amino Acid Bonding
• Amino acids are joined together by a peptide bond.
• Formed as a result of a dehydration synthesis reaction
Peptide Bond Animation
Peptide Bond
• How is it different than the dehydration
reaction we looked at with carbs and lipids?
BUILDING A PROTEIN
Amino acids are linked together to form
polypeptides
To become a “protein” a polypeptide must
be folded into a unique 3D shape
Only proteins have a “job”.
Polypeptides don’t “work” until folded
into a specific shape
4 LEVELS OF PROTEIN STRUCTURE
• PRIMARY – AMINO ACID SEQUENCE [CODED BY
YOUR GENES]
• SECONDARY – PLEATED SHEET OR HELIX
• TERTIARY – GLOB
• QUATERNARY – 2 OR MORE GLOBS TOGETHER
– Not all proteins go to this level!
http://whatscookingamerica.net/Eggs/EggDone2.jpg
DENATURATION
• LOSS OF SHAPE  LOSS OF FUNCTION.
• CAUSED BY HIGH TEMPRATURES, SALT, OR
pH CHANGES.
http://www.aeb.org/KidsAndFamily/images/color-broken-egg.gif
NUCLEIC ACIDS:
• Examples
– DNA [DEOXYRIBONUCLEIC ACID] –
RING OR HELIX, DOUBLE
STRANDED
– RNA [RIBONUCLEIC ACID] – SINGLE
STRANDED.
• FUNCTIONS
– INFORMATION STORAGE
– DIRECTIONS FOR HOW TO BUILD
PROTEINS  YOU!
NUCLEIC ACIDS:
• MONOMER  NUCLEOTIDE
– 5-Carbon Sugar +
– Nitrogenous Base
– Phosphate Group
• SUGARS – DEOXYRIBOSE OR RIBOSE
NUCLEIC ACIDS:
• NITROGEN BASES make the
nucleotides different
• DNA
Adenine (A)
•
Guanine (G)
•
Cytosine (C)
•
Thymine (T)
Structure of DNA
Two long chains of
nucleotides
– Connected between
ribose groups by
phosphates
– Paired nitrogen bases
(A-T; C-G)
Forms a double helix
with H bonds
DNA structure
• Two long chains of nucleotides
• Connected between ribose groups by phosphates
• Paired nitrogen bases (A-T; C-G)
• Forms a double helix with H bonds
a c t
s ps p
sp
g g
a
t g a
c c t
• Forms genes – units of genetic information
Relationship Between Proteins and
Nucleic Acids
• The order of amino acids in a protein
determines its shape and function.
• The DNA contains the instructions for the
sequence of amino acids in each protein.
• Errors or faults in the DNA can change the
function of the encoded protein.
Relationship Between Proteins and
Nucleic Acids (cont.)