Download Organic molecules (biomolecules)

ORGANIC MOLECULES
(BIOMOLECULES)
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ORGANIC MOLECULES
 Organic molecules are those that: 1)
formed by the actions of living things;
and/or 2) have a carbon backbone.
 Methane (CH4) is an example of this.
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If we remove the H from one of the
methane units below, and begin
linking them up, while removing
other H units, we begin to form an
organic molecule.
•
(NOTE: Not all methane is
organically derived, methane is a
major component of the atmosphere
of Jupiter, which we think is devoid
of life).
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When two methanes are combined,
the resultant molecule is Ethane,
which has a chemical formula C2H6.
Molecules made up of H and C are
known as hydrocarbons.
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FUNCTIONAL GROUPS
 Scientists eventually realized that specific
chemical properties were a result of the
presence of particular functional groups. F
 unctional groups are clusters of atoms
with characteristic structure and functions.
Polar molecules (with +/- charges) are
attracted to water molecules and are
hydrophilic. Nonpolar molecules are repelled
by water and do not dissolve in water; are
hydrophobic.
 Hydrocarbon is hydrophobic except
when it has an attached ionized functional
group such as carboxyl (acid) (COOH), then
molecule is hydrophilic.
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 Each organic molecule group has small molecules (monomers)
 Monomers can be joined together to form polymers that are the
large macromolecules made of three to millions of monomer
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that are linked to form a larger organic molecule (macromolecule).
subunits.
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 Macromolecules are constructed by covalently bonding monomers by condensation
reactions where water is removed from functional groups on the monomers.
polymers). Condensation involves a dehydration synthesis because a water is removed
(dehydration) and a bond is made (synthesis).
 When two monomers join, a hydroxyl (OH) group is removed from one monomer and a
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 Cellular enzymes carry out condensation (and the reversal of the reaction, hydrolysis of
hydrogen (H) is removed from the other.
•
This produces the water given off during a condensation reaction. Hydrolysis (hydration) reactions
break down polymers in reverse of condensation; a hydroxyl (OH) group from water attaches to one
monomer and hydrogen (H) attaches to the other.
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MAIN BIOMOLECULES
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THE MOST IMPORTANT
MACROMOLECULES IN
BIOLOGY…
 There are four classes of macromolecules (polysaccharides,
variety of functions in cells.
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triglycerides, polypeptides, nucleic acids). These classes perform a
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BIOMOLECULES
SUMMARY…
LAS PRINCIPALES MOLÉCULAS BIOLÓGICAS
Principales subtipos
(subunidades en paréntesis)
Ejemplo
Función
Carbohidrato:
normalmente contiene
carbono, oxígeno e
hidrógeno y tiene la
formula aproximada
(CH2O)n
Monosacárido: azúcar simple
Disacárido: dos monosacáridos
enlazados
Polisacárido: muchos
monosacáridos (normalmente
glucosa) enlazados
Glucosa
Sacarosa
Almidón
Glucógeno
Celulosa
Importante fuente de energía para las
células; subunidad con la que se hacen casi
todos los polisacáridos
Principal azúcar transportado dentro del
cuerpo de las plantas terrestres
Almacén de energía en plantas
Almacén de energía en animales
Material estructural de plantas
Lípido:
Contiene una proporción
elevada de carbono e
hidrógeno; suele ser no
polar e insoluble en agua
Tliglicerido: tres ácidos grasos
unidos a glicerol
Cera: número variable de ácidos
grasos unidos a un alcohol de
cadena larga
Fosfolípido: grupo fosfato polar
y dos ácidos grasos unidos a
glicerol
Esteroide: 4 anillos fusionados
de átomos de carbono, con
grupos funcionales unidos
Aceite, grasa
Ceras en la cutícula
de las plantas
Fosfatidilcolina
Colesterol
Almacén de energía en animales y algunas
plantas
Cubierta impermeable de las hojas y tallos
de plantas terrestres
Componente común de las membranas de
las células
Componente común de las membranas de
las células eucarióticas; precursor de otros
esteroides como testosterona, sales biliares
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Clase de molécula
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BIOMOLECULES…
LAS PRINCIPALES MOLÉCULAS BIOLÓGICAS
Clase de molécula
Proteína:
Cadenas de aminoácidos;
contiene carbono,
hidrógeno, oxígeno,
nitrógeno y azufre
Ejemplo
Función
Queratina
Seda
Hemoglobina
Ácidos nucleicos de cadena larga
Nucleótidos individuales
Acido
desoxirribonucleico
(ADN)
Acido Ribonucleico
(ARN)
Trifosfato de
adenosina (ATP)
Monofosfato de
adenosina cíclico
(AMP cíclico)
Proteína helicoidal, principal componente
del pelo
Proteína producida por polillas y arañas
Proteína globular formada por 4
subunidades peptídicas; transporta oxígeno
en la sangre de los vertebrados
Material genético de todas las células vivas
Material genético de algunos virus; en las
células vivas es indispensable para transferir
la información genética del ADN a las
proteínas
Principal molécula portadora de energía a
corto plazo en las células
Mensajero intracelular
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Acido nucleico:
Formado por subunidades
llamadas nucleótidos;
puede ser uno solo o una
cadena larga de
nucleótidos.
Principales subtipos
(subunidades en paréntesis)
(aminoácidos)
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Sugars…
CARBOHYDRATES
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CARBOHYDRATES

Carbohydrates have the general formula
[CH2O]n where n is a number between 3 and 6.

Carbohydrates function in short-term energy
 Sugars are structurally the simplest
carbohydrates.
storage (such as sugar); as intermediate-term energy
 They are the structural unit which makes
storage (starch for plants and glycogen for animals);
up the other types of carbohydrates.
and as structural components in cells (cellulose in the
Monosaccharides are single (mono=one)
cell walls of plants and many protists), and chitin in
sugars. Important monosaccharides include
the exoskeleton of insects and other arthropods.
ribose (C5H10O5), glucose (C6H12O6), and
fructose (same formula but different
structure than glucose).
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ALFA AND BETA GLUCOSE
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DISACCHARIDES
 are formed when two monosaccharides are chemically bonded together.
and fructose.
 Lactose, milk sugar, is a disaccharide composed of glucose and the monosaccharide
galactose.
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 Sucrose, a common plant disaccharide is composed of the monosaccharides glucose
 The maltose that flavors a malted milkshake (and other items) is also a disaccharide
made of two glose molecules bonded together
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DISACCHARIDES :
"DEHYDRATION
SYNTHESIS ".
When two monosaccharides are
joined together they form a
"disaccharide".
This linking of two sugars involves
the removal of a molecule of H2O
(water) and is therefore called a
"dehydration linkage". The
reaction is called "dehydration
synthesis".
e.g. Glucose + Glucose = Maltose
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 Polysaccharides
• These are long chains of
monosaccharides linked
together by dehydration
linkages.
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POLY SACCHARIDES
 are large molecules composed of individual monosaccharide units. A common plant
polysaccharide is starch which is made up of many glucoses (in a polypeptide these are referred
 Two forms of polysaccharide, amylose and amylopectin makeup what we commonly call
starch.
 The formation of the ester bond by condensation (the removal of water from a molecule)
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to as glucans).
allows the linking of monosaccharides into disaccharides and polysaccharides. Glycogen (see
Figure 12) is an animal storage product that accumulates in the vertebrate liver.
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CELLULOSE
(HOMOPOLY SACARID )
 is a polysaccharide found in plant
cell walls.
• Cellulose forms the fibrous
part of the plant cell wall.
• In terms of human diets,
cellulose is indigestible, and thus
forms an important, easily
obtained part of dietary fiber.
 As compared to starch and
glycogen, which are each made up of
mixtures of a and b glucoses, cellulose
(and the animal structural
polysaccharide chitin) are made up of
only b glucoses.
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HETEROPOLYSACARIDS
 Chitin: is an important structural material in the outer coverings of insects, crabs,
and lobsters. In chitin the basic subunit is not glucose (but N-acetyl-D-glucoseamine)
carbonate.
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in 1-4 linkages. These polymers are made very hard when impregnated with calcium
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Fatty acids
LIPIDS
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 are involved mainly with long-term
energy storage.
LIPIDS
 Fatty acids can be saturated (meaning
 They are generally insoluble in polar
substances such as water.
they have as many hydrogens bonded to their
carbons as possible) or unsaturated (with
one or more double bonds connecting their
 Secondary functions of lipids include
carbons, hence fewer hydrogens).
structural components (as in the case of
phospholipids that are the major building
block in cell membranes) and "messengers"
(hormones) that play roles in
 A fat is solid at room temperature, while
an oil is a liquid under the same conditions.
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communications within and between cells.
 Lipids are composed of three fatty acids
(usually) covalently bonded to a 3-carbon
glycerol. The fatty acids are composed of
CH2 units, and are hydrophobic/not water
•

The fatty acids in oils are mostly
unsaturated,
while those in fats are mostly saturated.
Lipids include the compounds
commonly known as fats, oils,
and waxes. We will look at three
important classes of lipids.
soluble.
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THE TRIGLYCERIDES
 Both fats and oils are
"triglycerides". These molecules
are made up of 3 long chain "fatty
acids" attached to a 3 carbon
molecule called "glycerol".
 The carboxyl and the fatty
acids are attached to the -OH
groups of the Glycerol via a
"dehydration synthesis" reaction to
yield an "ester" bond.
 Function: storage of energy "fat" in animals, and "oils" in
plants.
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 Animals convert excess sugars
(beyond their glycogen storage capacities)
into fats.
 Most plants store excess sugars as
starch, although some seeds and fruits
have energy stored as oils (e.g. corn oil,
peanut oil, palm oil, canola oil, and
sunflower oil).
 Fats yield 9.3 Kcal/gm, while
carbohydrates yield 3.79 Kcal/gm. Fats
thus store six times as much energy as
Fats and oils function in long-term energy
storage.
glycogen.
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SATURATED AND
UNSATURATED FATTY
Saturated Fatty Acid: These are fatty acids which
ACIDS
Unsaturated Fatty Acid: These are fatty acids which contain carbon-to-carbon
contain the maximum possible number of hydrogen
"double" bonds. Therefore since a carbon atom can have only 4 covalent bonds,
atoms. That is each carbon in the chain has two
there is one less bond available for hydrogen, therefore there is one less
hydrogen atoms attached to it. It is "saturated" with
hydrogen. (The carbons are not "saturated" with hydrogen atoms.)
hydrogen atoms.
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CLASS ACTIVITY
Directions.
1. Answer the next questions:
1. Work in teams of three
2. Read the next 6 slides
3. To generate a mindmap over all the 6
slides in a papersheet
4. Generate a table showing differences
between cis and trans
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1. What are satured and unsatured
fatty acids?
2. Are both of them good or bad for
your healthy?
3. What is an eicosanoid?
4. What is hydrogenation? What is
used for?
5. What are Cis and trans
configuration?
6. Which is best for your health of
both of them?
7. What is the meaning of LDL and
HDL and what is used for each
one of them?
8. Why is trans bad for your brain
and heart?
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FA T T Y A C I D C O N F I G U R A T I O N S
T R A N S FA T S : W H A T ' S U P W I T H
THAT?
Configurational isomers
What are Trans Fats?
 Cis configuration (oleic Acid)
 Double bonds bind carbon
atoms tightly and prevent rotation
of the carbon atoms along the bond
axis. This gives rise
to configurational isomers which
 Trans configuration (Elaidic
are arrangements of atoms that can
acid)
only be changed by breaking the
bonds.
Cis means "on the same side"
and Trans means "across" or "on
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the other side"
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HYDROGENATION AND
PARTIAL
HYDROGENATION?
 Unsaturated fats exposed to air oxidize to
 Hydrogen is incorporated into the fatty
create compounds that have rancid, stale, or
acid molecules and they become saturated
unpleasant odors or flavors.
with hydrogen. Oleic acid (C18:1) and
linoleic acid (C18:2) are both converted to
 Hydrogenation is a commercial chemical
stearic acid (C18:0) when fully saturated.
process to add more hydrogen to natural
unsaturated fats to decrease the number of double
bonds and retard or eliminate the potential for
rancidity.
 The liquid vegetable oil becomes a solid
saturated fat (shortening with a large
percentage of tristearin).
 Unsaturated oils, such as soybean oil, which
contain unsaturated fatty acids like oleic and
 By comparison, animal fats seldom have
linoleic acid, are heated with metal catalysts in the
more than 70% saturated fatty acid radicals.
presence of pressurized hydrogen gas.
In the table above, for example, lard has
54% unsaturated fatty acid radicals.
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METABOLISM OF FATS -WHY ARE TRANS FATS
BAD?

Metabolism of natural 20-carbon
polyunsaturated fatty acids like arachidonic acid
results in the biosynthesis of mediators with
Metabolism of natural C20 Cis fatty acids
produces powerful eicosanoids.
potent physiological effects such as
prostaglandins, prostacyclins, thromboxanes,
Although low levels of trans-vaccenic acid occur
naturally in some animal food products, partially
hydrogenated oils contain a large proportion of diverse
 These substances are known collectively as trans fatty acids.
eicosanoids because they contain 20 carbon
When large amounts of Trans fatty acids are
atoms (Greek eikosi = 20).
incorporated into the cells, the cell membranes and
leucotrienes, and lipoxins.

other cellular structures become malformed and do not
function properly.
However, polyunsaturated trans fatty acids
cannot be used to produce useful mediators
because the molecules have unnatural shapes
that are not recognized by enzymes such as
cyclooxygenase and lipoxygenase.
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TRANS IS BAD FOR YOUR
HEART…
 Trans fats are bad for your heart.
 Dietary trans fats raise the level of low-density lipoproteins (LDL or "bad cholesterol") increasing the risk
of coronary heart disease. Trans fats also reduce high-density lipoproteins (HDL or "good cholesterol"), and
raise levels of triglycerides in the blood.
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 Both of these conditions are associated with insulin resistance which is linked to diabetes, hypertension, and
cardiovascular disease.
 Harvard University researchers have reported that people who ate partially hydrogenated oils, which are high
in Trans fats, had nearly twice the risk of heart attacks compared with those who did not consume hydrogenated
oils. B
 ecause of the overwhelming scientific evidence linking Trans fats to cardiovascular diseases, the Food and
Drug Administration will require all food labels to disclose the amount of Trans fat per serving, starting in 2006.
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TRANS IS BAD FOR YOUR
BRAIN…

Trans fats are bad for your brain.

Trans fats also have a detrimental effect on the brain and nervous system. Neural tissue consists mainly of lipids and fats.

Myelin, the protective sheath that covers communicating neurons, is composed of 30% protein and 70% fat. Oleic acid and DHA are
two of the principal fatty acids in myelin.

Studies show that trans fatty acids in the diet get incorporated into brain cell membranes, including the myelin sheath that insulates

Trans fatty acid molecules alter the ability of neurons to communicate and may cause neural degeneration and diminished mental
performance.

Neurodegenerative disorders such as multiple sclerosis (MS), Parkinson's Disease, and Alzheimer's Disease appear to exhibit
membrane loss of fatty acids.

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neurons. These synthetic fats replace the natural DHA in the membrane, which affects the electrical activity of the neuron.
Unfortunately, our ingestion of trans fatty acids starts in infancy. A Canadian study showed that an average of 7.2% of the total fatty
acids of human breast milk consisted of trans fatty acids which originated from the consumption of partially hydrogenated vegetable oils
by the mothers.
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WHAT ARE OMEGA -3 AND
OMEGA-6 FATTY ACIDS?
 HOMEWORK: INDIVIDUAL! SEARCH ABOUT BOTH OMEGA ACIDS,
IN AT LEAST TWO DIFFERENT WEBSITES (OBVIOUSLY WiTHOUT
in the next website http://www.clo3.com/home.php
 Search for function
 Key benefits of omega 3
 Why are they so necessary for human diet
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LOOKING FOR IN rincondelvago, wikipedia, monografias, etc. You may look for
 Tridimensional shape
 DELIVERY FORM: VIA EMAIL TO [email protected]
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Since water is also a polar molecule the polar end of the
phospholipid is "attracted" to the + ends of the water
molecules. It is said to be "hydrophillic" (or water loving).
While the neutral end of the phospholipid molecule is nonpolar, i.e. is repelled by the "polar" water molecules, it is said to
be "hydrophobic" (water fearing).
PHOSPHOLIPIDS
 These molecules are structurally similar to the
triglycerides, but they differ in one important respect.
Triglycerides have 3 fatty acid chains, but the
phospholipids have only 2 fatty acid chains and one
phosphate (-) group.

The negatively charged phosphate group (and its
various end groups) cause this end of the molecule to
form a "polar" covalent bond with glycerol. That is
this end of the phospholipid molecule is "polar" while
the fatty acid chain is "non-polar".
 Therefore one end of the molecule is charged (-),
i.e. polar and the other end of the molecule is not
charged (neutral), i.e. non-polar.
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T H I S D U E L N AT U R E O F T H E
PHOSPHOLIPID MOLECULE MAKES
I T V E RY U S E F U L A S A C O M P O N E N T
O F C E L L M E M B R A N E S.
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AMINOACIDS, PEPTIDES
AND PROTEINS
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PROTEINS
These are very large 3 dimensional macromolecules. They are very important as
structural molecules in the cell, as energy sources, and most importantly as
"enzymes", (protein catalysts which speed up chemical reactions in the cell
without the need for high temperature or drastic pH changes).
Function
Structure
Motion
Defense
Almacenamiento
Signals
Catalysis
Main protein functions
Example
Colagen in skin, keratine in hair, nails and horns
Actine and miosine in muscles
Antibodies in blood stream
Zeatine in cornpops
Growth hormone in blood stream
Enzimes: they catalize almost every chemical reaction within cells, DNA
polimerase (produces DNA); pepsine (digers proteins); amilase (digers
carbohydrates); ATP synthetase (produces ATP)
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Proteins are often called "polypeptides" because they are made of long chains
of building blocks called "amino acids"
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STRUCTURE OF SOME
AMINO ACIDS
- R groups can be any of 20 different forms giving 20 naturally occurring amino
acids (in living things)
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STRUCTURE OF PROTEINS
 Primary Structure (or
primary level of
organization)
 Definition. "The
sequence of amino acids
in the polypeptide
chain.“
 Amino acids are bound
together with a "peptide"
bond.
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S E C O N DA RY L E V E L O F O R G A N I Z A T I O N
O F P O LY P E P T I D E S
 There are two types of secondary structure
in proteins, the α helix and the β pleated
sheet.
 The attraction of the R groups within the
same chain can cause the chain to twist into a
"right handed" coil.
 This " α helix" is held together by
hydrogen bonds between the hydrogen and
oxygen atoms of the amino acid backbone
(amino groups and carboxyl groups).
 Such "Intrachain Hydrogen Bonding"
Keratin is a structural protein found in hair and nails, skin, and tortoise shells.
The aHelix nature of wool is what makes it shrink.
often predominate in "globular proteins".
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 Another form of secondary structure
the β pleated sheet, is caused by hydrogen
bonding between the hydrogen atoms
(amino group) and the oxygen atoms
(carboxyl group) of amino acids on two
chains (or more) lying side-by-side.
 The β pleated sheet structure is often
found in many structural proteins, such as
"Fibroin", the protein in spider webs.
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THE TERTIARY
STRUCTURE OF PROTEINS
 When "proline", an oddly shaped amino acid
occurs in the polypeptide chain a "kink" in the
ahelix develops. Kinks can also be caused by
repulsive forces between adjacent charged R
groups. These kinks create a 3 dimensional chain
arrangement, ie. the "Tertiary" Structure
 This 3 dimensional shape is also held together
by weak hydrogen bonds but also by much
stronger "disulfide" bonds between two amino
acids of cystine ("covalent") disulfide "bridges"
(linkages)
 cystine -- s -- s -- cystine
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QUATERNARY
STRUCTURE OF PROTEINS
 This last level of organization is
simply taking 2 or more 3
dimensional (tertiary proteins) and
sticking them together to form a
larger protein.
 Many enzymes and transport
proteins are made of two or more
parts.
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STRUCTURE OF PROTEINS
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DENATURE
Proteins when heated can unfold or "Denature".
This loss of three dimensional shape will usually be accompanied by a loss of the
proteins function.
If the denatured protein is allowed to cool it will usually refold back into it’s
original conformation.
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NUCLEIC ACIDS
 These macromolecules include the
Ribonucleic Acids (RNA's) and the
Deoxyribonucleic Acids (DNA's).
 They are also long chain
macromolecules. The repeating
subunits (building blocks) of these
molecules are called "nucleotides".
 Nucleotides have three parts,
 a sugar (usually the six carbon
sugar ribose or deoxyribose), a
phosphate group (P04) and a base
(which contains nitrogen).
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BASIC STRUCTURE
 Nucleic acids form long chains by linking
the phosphate groups to the sugars. The
nitrogen bases stick out to the side. When
DNA is formed there are two chains of
nucleotides, each of which tends to coil
around the other forming the so called
"double helix".
 The two strands of DNA are said to form
the "DNA molecule".
 Note: that one strand runs in one
"direction" and the other strand runs in the
opposite "direction".
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Some differences between each nucleic acid
 Deoxyribonucleic acid (DNA) is
The DNA double helix.
composed of deoxyribose sugar and four
nitrogen bases, Complementary base
paired, as follows;
 Adenine = = = Thymine
 Guanine = = = Cytosine


 RNA differs from DNA in that there
is only one strand, and RNA uses ribose
as its sugar, and RNA substitutes Uracil
for Thymine.
 Adenine - Uracil
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 Guanine - Cytosine
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