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The Molecules of Life
or – Organic Chemistry in a Nutshell
Learning Outcomes (part 1)
Explain why/how carbon can form the basis for
so many different molecules.
Describe functional groups in organic molecules.
Describe the classes of macromolecules
and the building blocks of each.
Explain the terms macromolecule, polymer,
monomer, hydrophilic and hydrophobic.
Organic Compounds
The molecules that make up living
organisms are referred to as
ORGANIC compounds
-- based on carbon chemistry
-- contain lots of C, H, O, N,
-- also some S, P
Organic Compounds
The first organic compound
to be synthesized in vitro
was urea, in 1828.
C
H
O
N
Friedrich Wöhler
Why Carbon ?
What is so special about carbon?
It makes 4 covalent bonds
Emergent Properties: a corollary
Just because a molecule is an organic molecule
does not make it a biological molecule
C
H
O
N
Trinitrotoluene
Emergent Properties: corollary 2
Just because a molecule is an organic molecule
does not make it a biological molecule
C C C C C C C
C
Perfluorooctanoic acid (PFOA) or C-8
Organisms are made of Macromolecules
Macromolecule
Polymers
Monomer
polysaccharide
sugars
Lipids
triglyceride
fatty acids + glycerol
Proteins
polypeptide
amino acids
polynucleotide
nucleotides
Carbohydrates
Nucleic Acids
Organisms are made of Macromolecules
Macromolecules have different chemical
characteristics, depending on the
FUNCTIONAL GROUPS
in the molecule.
Functional Groups Determine
the Properties of Molecules
NAME
aldehyde
amine
carboxyl
STRUCTURE
Chemical
Characteristics
polar
polar, basic
polar, acidic
Functional Groups Determine
the Properties of Molecules
NAME
STRUCTURE
Chemical
Characteristics
hydroxyl
polar
methyl
non-polar
phosphate
polar
What difference can
one little functional group make?
estradiol
testosterone
Macromolecules are polymers
To make a polymer, monomers are joined
by a condensation reaction.
Macromolecules are polymers
To breakdown a polymer, monomers are separated
by a hydrolysis reaction.
Learning Outcomes (part 2)
Describe the functions of carbohydrates and the
roles of glycogen, starch, and cellulose
Describe the roles and the chemical characteristics
of lipids
Describe the four levels of protein structure
and explain the importance of proteins having
their correct structure.
Explain the differences between RNA and DNA
CARBOHYDRATES
• Used for energy storage
• Form structural components
Monomers are simple sugars or
monosaccharides –
C6H1206
... or ….
C(H20)n
CARBOHYDRATES
C6H1206
CH2OH
O
OH
CH2OH
OH
OH
fructose
CARBOHYDRATES
sucrose
https://youtu.be/I1SlBjbG7BQ
High Fructose Corn Syrup – do we care?
Coca Cola
35 grams of sugar
KFC 64 oz Pepsi
217 grams of sugar
780 calories
0 grams of fat
High Fructose Corn Syrup – do we care?
Can your body tell the difference?
Glucose is used by all organs in the body.
Fructose is used mainly by the liver.
High fructose intake -increases triglyceride levels in the blood
increases V-LDL levels in the blood
increases intra-hepatic fat levels
may contribute to obesity by encouraging
excessive calorie intake
International Journal of Obesity (2016) S6 – S11
High Fructose Corn Syrup – do we care?
DailyMail.com
CARBOHYDRATES
starch
CARBOHYDRATES
glycogen
CARBOHYDRATES
cellulose
LIPIDS
• Used for energy storage
• Form structural components of cell membranes
• Provide insulation (in animals)
LIPIDS
Lipids are structurally diverse
Major types of lipids fatty acids
triglycerides
phospholipids
hydrophilic
“head” (acidic
carboxyl
group)
LIPIDS
fatty acids
hydrophobic
“tail”
triglyceride
A stearic acid
(saturated)
B linoleic acid
(omega-6)
C linolenic acid
(omega-3)
LIPIDS
triglyceride
= glycerol + 3 fatty acids
LIPIDS
Fatty acid tails of lipids can contain double bonds
between carbons
LIPIDS
Trans-fats – Why do we care?
Trans-fats are created during the manufacturing
process of various prepared foods
Trans-fats – Why do we care?
Trans-fats have been linked to cardiovascular disease
because even very small amounts of trans-fats
greatly increase levels of
LDL cholesterol (“bad” cholesterol)
Cardiovascular disease is the leading cause of death worldwide
Trans-fats – Why do we care?
PHOSPHOLIPIDS
Hydrophilic head
Hydrophobic tails
phospholipids are
amphipathic
PHOSPHOLIPIDS
How will they react?
Steroids
CHOLESTEROL
PROTEINS
Proteins are
the workhorses of the cell.
Structural
Metabolism
Motility
PROTEINS
amino acids are the monomers for proteins
20 different amino acids are used in proteins
PROTEINS
functional groups in the R group result in
different chemical characteristics
CH2
OH
PROTEIN STRUCTURE
Primary Structure
Amino acids are covalently linked
to form a polypeptide
Secondary Structure
Secondary structures are maintained
by hydrogen bonds.
PROTEIN STRUCTURE
Tertiary Structure
3-D shape of a polypeptide
Quaternary Structure
2 or more polypeptides associate
to form a protein.
PROTEIN STRUCTURE
Why are we spending
SO MUCH TIME on protein structure?
Structure determines function
http://youtu.be/ub_a2t0ZfTs
PROTEIN STRUCTURE
Structure determines function
PrPc
PrPsc
NUCLEIC ACIDS
Store genetic information
(also have structural
or enzymatic roles in some RNAs)
deoxyribonucleic acid – DNA
ribonucleic acid – RNA
NUCLEIC ACIDS
Nucleotides are the monomers of DNA and RNA
Nucleotides have three parts
– phosphate, sugar, nitrogenous base
NUCLEIC ACIDS
In nucleic acids, the sugar and phosphate groups
form alternating units in a “backbone” and the
nitrogenous bases stick off to one side.