Organic Molecules
Macromolecules
What is an organic molecule?
Compounds that contain carbon are
considered organic
macromolecules are large organic
molecules
Why is carbon important?
Carbon has 4 electrons in its outer shell
Carbon can form 4 covalent bonds (it can
share electrons with up to 4 other atoms)
Usually shares with C, N, O, or H
(1:2:1)
Macromolecules
Large organic molecules
AKA polymers
Made up of smaller molecules called monomers
4 types
carbohydrates
lipids
proteins
nucleic acids (DNA and RNA)
How are macromolecules formed?
Dehydration synthesis!!!
AKA condensation reaction
Forms polymers by combining monomers
by removing a water molecule
H 20
OH
H
OH
+
OH
H
H
How are molecules separated?
Hydrolysis!
Breaks molecules apart by adding a water
molecule
H 20
OH
OH
H
H
+
OH
H
Carbohydrates
sugars
Carbohydrates
Can be small to large sugar molecules
Has many carbon - hydrogen bonds
4 types
simple sugars (ex. glucose)
starch
cellulose
glycogen
Saccharides
saccharide = sugar
monosaccharides (1 single simple sugar
molecule)
disaccharides (2 attached simple sugar
molecules)
polysaccharides (many attached simple
sugar molecules)
Monosaccharides
1 sugar unit C6H12O6
examples
glucose - major energy source for cells,
made by plants in photosynthesis
fructose - fruit sugar
galactose - milk sugar
ribose - sugar in RNA
deoxyribose - sugar in DNA
glucose
fructose
galactose
Disaccharides
2 attached sugar units
Examples
sucrose (table sugar)- 1 glucose + 1 fructose
lactose - glucose + galactose
maltose - glucose + glucose
sucrose
glucose / galactose
Polysaccharides
multiple sugar molecules attached in chains
Examples:
cellulose - makes up cell walls of plants
glycogen - stored glucose in animals
starch - stored glucose in plants
test for carbohydrates
Benedict’s solution tests for simple sugars
turns from blue to orange or red after boiling
Lugol’s (IKI / iodine solution)
turns from brown to black or purple
Lipids
oils and fats
Lipids
not soluble in water (don’t dissolve, soluble in hydrophobic
substances
more carbon - hydrogen bonds than carbs, fewer oxygen atoms
Store the most energy!!!!
Examples:
fats
oils
phospholipids
tryglycerides
Composition
glycerol molecule combined with 3 fatty
acids
2 types
saturated
unsaturated
saturated fats
all carbon atoms are joined by a single
bond; no double bonds
animal fats
solids at room temperature
Unsaturated Fats
Double bonds present between carbons
plant fats
liquids at room temperature
Functions
1. Used for long term energy storage
2. insulate and waterproof the organism
3. protect against physical shock
4. protection against water loss
5. chemical messengers
6. major component of membranes
Test for lipids
spot test
place a suspected lipid on a piece of
brown paper
look for a “shiny” spot
Proteins
polypeptides
Proteins
AKA polypeptides
composed of C, H,
O, N, and
sometimes Sulfur
made up of 20
different amino acids
bonded by
peptide bonds
Amino Acids
made of an amino group (-NH2) and a carboxyl
group (-COOH) bonded to a side chain
side chain is different in every amino acids
Peptide bonds exist between the amino group of
one A.A. and the carboxyl group of another A.A.
8 essential A.A. that must come from food
humans can make the other 12
Shapes
3 dimensional shapes
determined by amino acid arrangement
shape determines function
4 levels of structure
primary structure
secondary structure
tertiary structure
quaternary structure
primary structure
amino acids are bonded by peptide bonds
in straight chains
aa 1
aa 2
aa 3
aa 4
aa 5
secondary structure
3D folding of a primary structure into a
coil or pleats held together by H bonds
tertiary structure
secondary structures bent and folded into
more complex 3D shapes of joined
polypeptides
called a subunit
Quaternary structure
2 or more subunits
globular shape
form in aqueous environments
make enzymes (ex. hemoglobin)
Functions
function
explanation
catalyst
enzymes that speed up reactions
storage
small molecules can be joined with proteins for storage
transport
channel proteins help substances through the cell membrane
messenger
hormones are used as signals
antibody
antibodies bind to destroy foreign substances
regulation
help maintain homeostasis
structure
provide support for the body including mechanical support,
and structure. Hair and bone
Test for proteins
http://faculty.kirkwood.edu/apeterk/learningobjects/
biologylabs.htm
Biuret solution
place a drop of biuret solution in a
suspected protein solution
color changes from blue to purple in the
presence of a protein
Nucleic Acids
Nucleic Acids
made of chains of
nucleotides
linked by dehydration
synthesis
2 types
deoxyribonucleic acid
(DNA)
ribonucleic acid (RNA)
Nucleotides
Made up of a:
phosphate group
pentose sugar
Includes:
Adenine
Thymine
Cytosine
Guanine
Uracil
Enzymes
•
Special Proteins
Chemical Reactions
•
•
•
All chemical reactions have products and
reactants
Reactants go in - substrates
Products come out
6H2O + 6CO2
C6H12O6 + 6O2
Biochemical Reactants
•
Enzymes are catalysts
•
They speed up reactions
•
They are not changed by reactions
Enzymes as specific catalysts
Shape
•
Enzymes have a specific shape
that allows them to function
•
•
Depends on amino acids
and how they’re folded
Shape only lets the enzyme
interact with certain molecules
•
•
Shape of substrate and
active site of the enzyme are
opposite
Lock and key fit
In a reaction…
•
•
•
Substrates and enzymes come together by
intermolecular forces to form an enzyme –
substrate complex
Enzyme changes shape to complete the
reaction and put the molecules together
When the reaction ends they separate and the
enzyme is available to repeat the process –
NOT USED UP
enzyme-substrate complex
Activation Energy
•
•
In chemical reactions
bonds must be broken
and new ones made
Enzymes lower the
amount of energy
needed – they reduce
the activation energy
Factors affection function
•
•
•
Any factors that influence
chemical reactions influence
enzyme productivity
Enzymes from different
organisms work best at different
temperatures and different
enzymes work best at different
pH levels
Factors:
•
Temperature
•
pH
•
Concentration of enzyme and
substrate
Destroying Enzymes
•
•
•
Some of the same things that affect function
can affect the shape of an enzyme
If an enzyme is folded into an unusable shape it
has been denatured
Factors that denature enzymes:
•
High temperatures
•
High or low pH
Important Enzyme Reactions
•
•
All cells have certain enzymes
•
Ex – enzymes to break down glucose for
energy
Specialized cells have specialized enzymes
Special Enzymes and
Fucntions
•
•
•
•
•
-ase = enzyme
Carbonic Anhydrase – keeps carbon dioxide
from building up in the blood
Lipase – speeds up digestion of lipids
RNA polymerase – speeds up transcription of
DNA to RNA for making proteins
The inability to make some enzymes can lead to
disease – such as Tay – Sachs and Cori
disease