Transcript Organic Compounds

Organic Compounds
Necessities for Life
What is an organic compound?
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In Biology, the word organic means “relating
to organisms” NOT food grown without the
use of pesticides, antibiotics, or other
industrial chemicals.
All organic compounds contain covalently
bound carbon.
Organic compounds can also be synthesized
in the lab.
The Chemistry of Carbon
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Carbon atoms have four valence (outer shell)
electrons, allowing carbon to form covalent bonds
with many elements including hydrogen, oxygen,
phosphorus, sulfur and nitrogen.
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Carbon can also bond to other carbon atoms, which
gives carbon the ability to form chains that are almost
unlimited in length.
These carbon-carbon bonds can be single, double, or
triple.
The chains be straight, branched, or even ring-shaped.
Therefore, carbon is unique in that it can form millions
of different large and complex structures.
MACROmolecules are giant and are. . .
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formed by
polymerization, in which
large compounds
(polymers) are built
from joining smaller
units (monomers)
together.
Four Groups of Organic Compounds
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Carbohydrates, lipids, nucleic acids, and
proteins are needed by all living things.
Carbohydrates
(sugars)
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main source of energy for organisms
can also be used for structural purposes
made of C, H, and O; usually in a 1:2:1 ratio
The monomers of carbohydrates are called
monosaccharides, like glucose, fructose (in
fruits) and galactose (in milk).
The breakdown of monosaccharides supplies
immediate energy.
usually end in –ose.
Carbohydrates cont’d
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Extra sugar is
stored as
macromolecules
called
polysaccharides.
Polysaccharides are
made from
monosaccharides.
Uses of Polysaccharides
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Many animals store extra sugar as glycogen.
Glycogen stored in your muscle supplies
energy for contractions. Glycogen stored in
your liver is released when glucose in your
blood runs low.
Plants store excess sugar as starch.
Plants also make cellulose, a strong, rigid
fiber used for support.
Lipids
(fats, oils, and waxes)
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uses: long-term energy storage, insulation,
waterproof covering, part of biological
membranes, chemical messengers (steroids)
contain mostly carbon and hydrogen
generally not soluble in water
Lipids
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Many lipids are formed when a glycerol molecule combines
with fatty acids.
If all carbon atoms have only single bonds, the lipid is
saturated. It holds as many hydrogen atoms as possible.
Lipids
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If there is at least one
double bond between
carbon atoms, the lipid
is unsaturated.
Unsaturated lipids like
cooking oils tend to be
liquid at room
temperature.
Nucleic Acids
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store and transmit
hereditary, or genetic,
information
contain hydrogen, carbon,
nitrogen, oxygen, and
phosphorus
The monomers of nucleic
acids are nucleotides, which
contain three parts: a 5carbon sugar, a phosphate
group, and a nitrogen base.
examples: DNA and RNA
Proteins have many functions
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They can provide structural
support in bones and
muscles, form parts of cell
membranes, function as
hormones to regulate the
body, form antibodies to
protect against infection, and
increase the rate of chemical
reactions to name a few.
Proteins are macromolecules.
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contain nitrogen, carbon, hydrogen, and
oxygen (most also have sulfur)
The monomers of proteins are amino acids.
Amino acids contain an amino group, a
carboxyl group, and a variable R-group.
• When the amino acids join, they form a polymer
called a polypeptide. The monomers are held
together by peptide bonds.
• More than 20 different amino acids are found in
nature.
• Since the R-group varies, it allows for much
variety. That is why proteins have so many
functions.
Proteins have four levels of
organization.
• This allows for the
unique shape of
proteins.
• Shape is very
important; if a protein
is not the right shape,
it will not work.
Enzymes – a special type of protein
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Enzymes are biological catalysts, which work
to speed up a chemical reaction.
Without enzymes, several reactions in cells
would never occur or happen to slowly to be
useful.
Enzymes lower activation energy.
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Activation energy
is the energy
needed to get a
chemical reaction
started.
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When
activation
energy is
lowered,
the
reaction
speeds up.
Enzyme Action
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Enzymes provide a site
where reactants can be
brought together to
react.
This is site is called the
active site.
The reactants are called
the substrates.
The shape of an enzyme
is so specific that
generally only one
enzyme will work for one
substrate.
Therefore, enzymes are
said to fit together like a
“lock and key.”
Enzyme Action
Since only the
substrate
changes
during the
reaction, the
enzyme can
be reused
again and
again.
Enzymes can be turned on and off.
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Enzymes work best at specific
temperatures and pH.
Heating can change the enzyme shape
and the wrong pH affects the binding of
the substrate to the enzyme.
Ergo, enzymes in our body work best at
37°C (98.6°F) and at a pH between 6.5 to
7.5.
Also, most cells contain proteins that turn
enzymes on or off during critical stages of
development.