Molecules of Life
Organic Molecules
Biological Molecules
Organic MoleculesWhy is this important?Cells are mostly water and carbon-based
moleculesCarbon has a valence of 4 so it will form a
tremendous variety of large, complex and diverse molecules
Large variety of molecules = diversity of life
Unity in DiversityAll life is composed of carbon
compounds (UnityUnity) DiversityDiversity of life is due to various ways
carbon can be assembled Organic chemistryOrganic chemistry = study of the
compounds formed by carbon
Organic ChemistryThe four valence electrons in carboncarbon
enable it to be bonded in four different directions
Usually forms COVALENT bonds with Hydrogen
Often oxygen, nitrogenFour most common elements are: CHON
6+
1
1
1
1
C H H
H
H
C C H
H
H H
H
H
C C H
H
H H
H
C
C C C C
C C C
C
C C C C C C C C
CC C C C C C C
CC C C C C C C
C C
C C C C C C
CC C C C C C C
C CC C C C C C
CC C C C C C
C
C OH H
H
H
C OH N
H
H
H
H
C OH H
H
H
HN
Organic Chemistry
Functional groupsFunctional groups – clusters of atoms that have a specific role on the molecule
OHOH – hydroxide (polar) NHNH22 – amino (polar)
COOHCOOH – carboxyl (polar) CHCH33 – methyl (nonpolar)
Organic Chemistry
C
C
CC
C
C
Rings H
H
H HHH
H
H
HHH
H
Each carbon has 4 bonds
Organic Chemistry
C
C
CC
C
C
Rings
Sometimes the carbon atoms form double bonds with
itself
Benzene ring
Organic Chemistry
C
C
CC
C
C
Rings OH
O
Organic Chemistry
OC
CC
C
C
OH
O
C
Organic ChemistryFunctional groups change the chemical
properties of a moleculeThe great diversity of life is caused by only
a few molecules with different arrangements of FUNCTIONAL GROUPS
BiochemistryBiochemistry - chemistry of living things
Differences in functional groups The rearrangement of FUNCTIONAL GROUPS on a molecule causes major changes in its function
BiochemistryFour basic carbon molecules important
to all living things:CarbohydratesLipidsProteinsNucleic acids
BiochemistryBiochemistry
The four basic molecules are long The four basic molecules are long chains of smaller molecules linked chains of smaller molecules linked togethertogether
A train formed by various types of A train formed by various types of carscars
Biochemistry
Smaller molecules are called
MONOMERSMONOMERSLong chains are called………POLYMERSPOLYMERSPolymers are large molecules MACROMOLECULESMACROMOLECULES – large
polymer
What You Have to Know: For each of the 4 types of molecules:
1. How each molecule is formed
2. The types and names of the monomers
3. The role of each molecule in life
How Are Organic Compounds Formed?
Monomers = smaller functional molecules that can be linked together
Macromolecule = ‘large molecule’
Polymers = macromolecules formed by linking monomers together
PolymerizationPolymerization
Many monomers are linked Many monomers are linked together to form macromoleculestogether to form macromolecules
Dehydration synthesisDehydration synthesis
Monomer Monomer Monomer Monomer
How Are Organic Compounds Formed?
Dehydration synthesisDehydration synthesis; p. 41OH- combines with OH- from adjacent
monomer (molecule)OH + OH = HOH + OHOH = H2O
How Are Organic Compounds Formed?
Dehydration synthesisDehydration synthesis polymers are formed from monomers by the removal of water
All four compounds important to life are formed by dehydration synthesisdehydration synthesis
Macromolecules – dehydration synthesis
Monomers/Polymers
Dehydration synthesis: building polymers
Hydrolysis: breaking down polymers into monomers
4 Types of Macromolecules
Carbohydrates Lipids
Proteins
Nucleic acids
CarbohydratesSugars; three types:
Monosaccharides ‘one sugar’DisaccharidesDisaccharides ‘two sugar’PolysaccharidesPolysaccharides ‘many sugar’
Carbohydrates Carbon, hydrogen, oxygenC(n)H2O
C6H12O6 – glucose
C6H12O6 - fructose
C5H10O5 - ribose
C12H22O11 – sucrose
Carbohydrates – MonomersSimple sugarsMonosaccharides – ‘one sweet’
Glucose, fructose, ribose, deoxyribose, galactose
Most monosaccharides are used as a source of energyenergyRibose and deoxyribose form part of
the structure of DNA, RNA
Carbohydrates: MonomersGlucose; #1 sugar, most used sugar for
energy, all organismsFructose; very sweet; fruits
Di-saccharides Di = ‘two’Two monosaccharides joined together
by…. DEHYDRATION SYNTHESISDEHYDRATION SYNTHESISEnergy storage
DisaccharidesGlucose + glucose = maltose;
germinating seeds, malt in beerGlucose + fructose = sucrose; table
sugarGalactose + glucose = lactose; milk
Disaccharides
Sugars a Major Cause of a Tooth Decay
Feed bacteria
Polysaccharides ‘Poly’ = manyLong chain of monosaccharidesStarch GlycogenCellulose
Carbohydrates - Polysaccharides
‘poly’ – manyMany monosaccharides =
polysaccharidepolysaccharideMacromolecule
Carbohydrates - Polysaccharides
Examples:CelluloseCellulose – used to make cell walls
of plants; indigestible without bacteria in gut; fiber
StarchStarch – stored glucose in plantsGlygogen – stored glucose in
animals
Carbohydrates: FunctionsEnergy storageStructure = plant cell wallsMonosaccharidesDisaccharidesPolysaccharides
Types of Macromolecules
Carbohydrates
LipidsProteins
Nucleic acids
Lipids Three types of lipids:
TriglyceridesTriglyceridesPhospholipidsPhospholipidsSteroidsSteroids
Lipids - TriglyceridesExamples:
Fats Oils Waxes
Insoluble in water - nonpolar
Triglycerides Glycerol + three fatty acidsDehydration synthesis Lots of C-H bonds; lots of energy
Triglycerides 2 types of triglycerides:
SaturatedSaturated UnsaturatedUnsaturated
Saturated fats have no double bonds; are full (saturated) with hydrogen
Saturated fat – fatty acids, full of hydrogen
Unsaturated fat – fatty acids with double bonds; less hydrogen; less energy
Saturated fatty acids
Unsaturated fatty acid
Types of FatsSaturated
No double bondsSaturated w/ HSolids @ (200)Animal fatsBacon grease,
lard, butter
Unsaturated Double bond(s)UnsaturatedLiquids @ (200)Plant fats (oil)Corn, peanut,
olive oils
Triglycerides Link (?) between saturated fats in diet
and arteriosclerosis
Fats: Functions Store energyStore energy
More energy in fats than in carbohydrates; birds eat sunflower seeds first (fats)
Padding (eye, other organs) Insulation (keep you warmer; seals,
whales)
Fats Oils: Waterproofing -
Lipids - PhospholipidsTriglyceride - One of the fatty acid ‘tails’
is replaced with a phosphate groupPhospho – lipidMajor component of cell membrane
Fatty acids
Lipids: Steroids
Sex hormonesSex hormones:
Testosterone; maleTestosterone; maleEstrogen; female
Lipids: Steroids Anabolic steroidsAnabolic steroids = artificially created
testosteroneMimics male hormone Increased muscle massDecreased sex drive, infertilityHeart, liver problems
Lipids - Steroids Insoluble in water (nonpolar)Very different from other lipids in
structure4 fused carbon rings with various
FUNCTIONAL GROUPSFUNCTIONAL GROUPSCholesterol – basic molecule used in
cell membrane; also used to make other steroids (estrogenestrogen and testosteronetestosterone)
Cholesterol
Cholesterol
Lipids - Steroids Anabolic steroidsAnabolic steroids – synthetic variations of
testosterone Builds muscle and bone mass during
puberty; maintains male characteristicsUsed in 1950’s to treat anemia and muscle
diseasesAbused by athletes; linked to liver damage,
cardiovascular, mood swings
Proteins Protein – ‘first place’Composed of AMINO ACIDSAMINO ACIDS
(monomers)20 different kinds of amino acids
Amino group
Carboxyl
COOH
Amino group
Side groupSide group
Carboxyl
COOH
Amino group
Amino AcidsDifferences between the 20 amino acids are
caused by different R (side) groupsAmino acids are linked together by
dehydration synthesisBonds formed between amino acids are
PEPTIDE BONDSPEPTIDE BONDSLong chain of peptides = = polypeptidepolypeptide
p. 72
Different amino acids caused by different side groups
Proteins Peptide bond – bond formed between
two amino acids (dehydration synthesis)Long chain of peptides = POLYPEPTIDEPolypeptides - proteins
•Amino acids are linked together in a SPECIFICSPECIFIC sequence. Conformational shape
•If the sequence gets messed up, the protein may not function. May be fatal or only cause health problems
•Denaturation
Protein’s Shape H bonding helps determine shape Breaking the H bond changes the shape of
the protein – DENATURATION; Heat - cooking changes the shape of
proteins; turn brown; eggs turn white Poisons – chemicals change shape by
interrupting bonds (acids, bases, acetone)
Proteins - Functions
1.1. StructureStructure – feathers, hair, muscle, nail, horn
2.2. EnzymesEnzymes – speed up reactions
3.3. HormonesHormones – chemical messengers
4.4. CarriersCarriers – hemoglobin carries oxygen to cells
Nucleic Acids - Monomers
Monomers – NUCLEOTIDESNUCLEOTIDESNucleotides:
A simple sugarA phosphate groupphosphate groupA NITROGENOUS BASENITROGENOUS BASE
Adenine always bonds with Thymine
Cytosine always bonds with guanine
A-T
C-G
H bonding
A T T C C G C A T G G G T C T T T T
T A A G G C G T A C C C A G A A A A
TACCATACTTTCGGCTACTTTTGGG
DNA sequence = “genetic code”
If A-T and C-G, what is the complimentary strand?
TACCATACTATAGGCTACTATTGGG
ATGGTATGATATCCGATGATAACCC
Similarities in DNA sequences indicates close evolutionary relationship