Download Biological Macromolecule and Their Subunits

Biological Macromolecule and Their Subunits
Livings things are complex, however, at their roots the fundamental molecular components of life may
seem surprisingly simple. Remember, biological molecules are made almost entirely of just 4 elements:
Carbon
Hydrogen
Oxygen
Nitrogen
Molecules containing carbon are known as _____________________________ compounds. They were
originally given this name because 19th century scientists believed that they could only be synthesized by
living things using “vis vitalis” (meaning “life force”). We now manufacture organic molecules in many
different forms, from medicines to plastics. Organic molecules behave predictably in accordance with all
of the known laws of chemistry and physics. (Sorry, you may not be as “special” as was once thought)
How can such complexity be achieved from so few building blocks? The short answer to this question
can be found by understanding polymers. These are large molecules made from repeating subunits.
Cells are composed almost entirely by just 4 different types of macromolecules which are in fact
polymers. You will remember these from grade 11. Name the types macromolecules depicted below:
A:
B:
(monomer)
C:
D:
(monomer)
THE BASICS OF ORGANIC CHEMISTRY
Since carbon can form 4 covalent bonds. This makes it a very versatile molecule, often bonding with
other carbon molecules to form long chains. The simplest organic molecules are hydrocarbons which
contain only carbon and hydrogen.
Build models of the following hydrocarbons, then draw their structural diagram in the space provided
the space provided:
Methane CH4
Ethane C2H6
Hexane C6H14
Ethene C2H4
Ethyne C2H2
Cyclohexane C6H12
Since C—H bonds are non-polar, hydrocarbons are hydrophobic and therefore not often found in living
things. By adding elements like oxygen and nitrogen to hydrocarbons they will gain polar regions and
will often increase their solubility in water. Also, depending on the arrangement of elements added, the
organic compound will gain a new 3D shape and new chemical properties allowing it be involved
chemical reactions or to serve a particular function. The common stable arrangements of elements that
can be added to hydrocarbons are called the FUNCTIONAL GROUPS.
** Complete the summary table of functional groups on the following page**
Build models of the molecules shown below then identify the functional groups present and name the
type of organic molecule:
Acetic acid (vinegar)
Isopropanol
Methylamine
OH
CH
H3C
CH3
Functional group present:
Functional group present:
Functional group present:
Type of molecule:
Type of molecule:
Type of molecule:
THE FUNCTIONAL GROUPS
Functional
Group
hydroxyl
carbonyl
carboxyl
amino
sulfhydryl
phosphate
Chemical Formula
Name of Compound
Example
MOLECULAR ISOMERS:
The macromolecules can be thought of as molecular machines. Their 3D shape is just as important as
their chemical and physical properties in determining their biological functions. From this perspective,
understanding the arrangement of atoms and the shape of a molecule is critically important.
Define isomer
Two main types of isomers:
1) Structural isomers _____________________________________________________ Eg.
_____________________________________________________
_____________________________________________________
2) Stereoisomers -
_________________________________________________________________________
_________________________________________________________________________
Two types of stereoisomers
A) Geometrical isomers
Changes the structure of the molecule giving it:
B) Optical isomers
- different ________________________ properties
Molecules that are ______________ ______________
of each other (not superimposable).
- often retains ______________________ properties
Usually have similar chemical and physical properties.
Enzymes or membrane proteins can distinguish them
giving them different biological properties. (Usually one is
biologically active the other is biologically inactive)