Transcript Chapter 2: Biochemistry

Inorganic compounds include all that do
not contain carbon, and all that contain
simple carbon, but no hydrogen. They are
found in living and non-living substances.
Organic compounds contain both carbon
and hydrogen. Usually they also contain
nitrogen and oxygen. They are found in
living organisms.
H2 O
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Contains both carbon and hydrogen, and
usually nitrogen and oxygen
Found only in the bodies or remains of
living things
Each carbon atom forms four bonds with
other atoms (usually double bonds, triple
bonds are rare, yet existent)
Carbohydrates, lipids, proteins and
nucleic acids are four major types of
organic compounds
> Any compound that
does not contain the
element carbon is
inorganic
> Examples of inorganic
compounds are carbon
dioxide, calcium
carbonate, water, salts,
phosphates, bases and
certain acids such as
hydrochloric acid
Four types of organic compounds will
be discussed in this chapterCarbohydrates, Lipids, Proteins and
Nucleic Acids.
Carbohydrates are compounds of carbon,
hydrogen and oxygen in which the ratio
of hydrogen to oxygen is 2 to 1. Simple
sugars, or monosaccharides, are the
simplest carbohydrates. Examples of
monosaccharides are glucose, fructose
and galactose.
Dehydration synthesis is a type of
reaction in which two molecules are
bonded together by the removal of
water. Joining two
monosaccharides by dehydration
synthesis forms a disaccharide like
maltose or sucrose. Many organic
compounds are polymers that have
long chains of repeating units. A
polymer formed by joining many
sugar molecules end to end is called
a polysaccharide.Starch, glycogen
and cellulose are examples of
polysaccharides.
A lipid is an organic compound,
other than a carbohydrate, that
consists of carbon, hydrogen, and
oxygen. Lipids go by the common
names, fats, oils and waxes. Lipids
are formed from the combination
of fatty acids and glycerol. A fatty
acid is an organic acid due to the
fact that it contains a carboxyl
group. Glycerol is an alcohol, or
an organic compound that
resembles a base in having one or
more OH groups in their
molecules. Glycerol has 3 OH
groups in its molecule.
The fats that are solid at room temperature are just
referred to as fats. The fats that are liquid at room
temperature are referred to as oils. If all the carbonto-carbon bonds are single bonds, that fat is said to
be saturated. If one or more pairs of carbon are joined
by a double or even triple bond, they are said to be
unsaturated fats. If a fat just has one unsaturated
bond, it is known as monounsaturated. If it has more
than one it is known as polyunsaturated. Unsaturated
fats can be changed to saturated fats through
hydrogenation, or adding hydrogen to it.
Saturated and Unsaturated Fatty
Acids
Waxes are formed by the combination fatty
acids and alcohols other than glycerol.
Cholesterol is a steroid found in most animal
tissues. It plays a role in the buildup of fatty
deposits in arteries. Lipids have an extreme
importance in many life activities. They are
components of cell membranes along with
other cell structures. Lipids also provide a
great energy supply and serve as cushioning
and insulation for the body.
Fatty Acid
What is the name of the functional group on the
right (-COOH) that makes this an acid?
A carboxyl acid group
Dehydration Synthesis of a Fat
Glycerol ↑ + 3
Fatty Acids ↓
Yields a Fat 
Proteins are compounds that consist of nitrogen, in
addition to carbon, hydrogen and oxygen. They serve as
enzymes, antibodies, contractile material, hormones,
pigments and structural parts in cells and tissues. Proteins
also contain one or more chains of amino acids, the
structural units of proteins. Glycine and alanine are
examples of amino acids. If two amino acids are joined by
dehydration synthesis, a peptide bond forms between
them. The resulting molecule is a dipeptide. A polypeptide
is a chain of amino acids formed by a peptide bond.
Protein Synthesis (Formation of a
Peptide Bond)
Click on the above link to see the
formation of a peptide bond
Enzymes are large, complex
proteins. They make it possible for
chemical reactions to occur in living
cells.They are organic catalysts,
because they can affect a reaction
without being changed itself. An
enzyme acts upon a substrate. The
names of the enzymes usually ends
with the suffix ase, and the name is
often derived from the substrate. For
example, maltase is the enzyme that
splits one maltose molecules into two
glucose ones.
Enzymes increase the rate of a reaction by
decreasing the amount of activation energy
needed to start the reaction
Somewhere on the surface of an enzyme, there is an active
site. The substrate molecules fit the shape of the active site.
It then forms a temporary union with the enzyme called
the enzyme-substrate complex.The substrate may then
break bonds within the substrate molecule and thus
separate it into two smaller molecules. This is called the
lock-and-key model because the notched surface of a key
can open only one lock, just like the shape of the active site
of an enzyme fits the shape of only certain substrates.
Method of Enzyme Action
What process is taking place in the
above diagram?
Hydrolysis of a
disaccharide
#5
Since sucrose is what the
enzyme works on, it is call
the __________________.
Substrate
#5 is known as the
Enzyme-substrate complex
Induced Fit vs. Lock and Key
The lock and key
model is a perfect fit
between the substrate
and the enzyme.
The Induced fit
model suggests that
when the substrate
enters the active site,
the enzyme changes
its shape to perform
work on the substrate.
• Small amounts of an enzyme can affect large quantities of a
substrate
• Enzymes enable cell reactions to proceed at normal
temperatures
• Enzymes work best at certain temperatures
• Each enzyme works best at a certain pH
• The rate of an enzyme-controlled reaction depends on the
concentrations of enzyme and substrate
• Some enzymes need substances called coenzymes, or a
nonprotein organic substance necessary to the functioning
of a particular enzyme, in order to function
• Some enzymes function inside the cell, others act outside
the cell.
Graph showing the affect of
temperature on enzyme action.
What does this graph show?
The affect of
pH on
enzyme
action
What do most
enzymes end
in?
-ase
Review of Carbohydrates
1)Carbohydrates
2)Proteins
3)Lipids (Fats & Oils)
4)Nucleic Acids (DNA & RNA)
1) Main source of energy for cell activities
2) 2:1 Ratio of Hydrogen to Carbon C6H12O6
3) Examples: Glucose (sugar) & Starch