ACTIVITY I-ORGANIC CHEMISTRY
ORGANIC CHEMISTRY IS THE STUDY OF CARBON BASED MOLECULES
Cells can produce complex molecules by biosynthesis reactions, cells are also
composed of complex molecules, and complex molecules carry out the functions of
cells. These complex molecules are known as biomolecules. Biomolecules are
organic molecules that are produced by living things. Organic molecules are
molecules or compounds that contain the element carbon. Molecules found in all
living organisms are primarily made of chains of carbon atoms with hydrogen,
oxygen, and nitrogen atoms attached. The carbon chain serves as the backbone or
skeleton for other atoms to attach.
Lets discover why carbon is one of the best elements to serve as the backbone for
forming long and complex molecules.
REASON NUMBER 1:
Recall carbon has an atomic number of six and a mass number of twelve. Draw a
carbon atom (show nucleus with correct number of protons and neutrons and
energy levels with correct number of electrons in each energy level).
1.
2.
3.
4.
5.
How many electrons does carbon have?
How many electrons are in carbon’s first energy level?
How many electrons are in carbon’s second energy level?
How many bonds can carbon make?
Will carbon share, gain or lose electrons to make bonds?
THUS THE FIRST REASON CARBON IS ONE OF THE BEST ELEMENTS FOR FORMING
LONG AND COMPLEX MOLECULES IS:
________________________________________________________________________________________________
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REASON NUMBER 2:
1. Open the molecular model kit. Place the black carbon atoms in one
compartment of a petri dish.
2. Observe the carbon atom and note that it has four projections. Each
projection represents outer energy level valence electrons.
a. How many valence electrons does carbon have?
b. To be a stable element, how many electrons does carbon need?
c. How can it acquire the number of electrons needed?
3. Using your model connect two carbons together, then three carbons, then
four, and then five carbons?
a. How many different size carbon chains did you make?
b. Can you make other size carbon chains if you had enough carbon
atoms?
4. Now connect three carbon atoms together. Connect another carbon atom to
middle carbon and then add another carbon to the carbon just added.
a. This is a branched structure. Using your model construct a
different branched carbon molecule (show teacher before moving
forward).
b. Using twelve carbons, draw three different branched structures.
5. Connect five carbon atoms into a chain. Connect the first carbon in the chain
with the last carbon in the chain.
a. What type of structure did you form?
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6. Look at the drawings of different organic molecules below and indicate if they are
chains, branched structures, ring structures, or combinations. If a combinations, list
the combination (i.e. Chain and ring).
PROPANE
ISOPENTANE
BENZENE
HISTIDINE
7.Living things do not make benzene, isopentane, and propane. Living things make
histidine. For each item below indicate if it is an organic molecule, biomolecule, or
both? Give a reason for your answer.
a. BENZENE ________________________________________________________________________
b. HISTIDINE _______________________________________________________________________
c. PROPANE ________________________________________________________________________
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d. ISOPENTANE _________________________________________________________________
THUS THE SECOND REASON CARBON IS ONE OF THE BEST ELEMENTS FOR
FORMING LONG AND COMPLEX MOLECULES IS:
________________________________________________________________________________________________
REASON NUMBER 3:
1. Connect two carbon atoms together. Connect another two carbon atoms
together but use two connectors. Connect another two carbon atoms
together but use three connectors.
a. Would each of these models represent the same or different
molecule? Why?
b. Look at the diagrams below. Do you think they will be different
molecules with different physical and chemical properties? If so,
what makes them different?
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THUS THE THIRD REASON CARBON IS ONE OF THE BEST ELEMENTS FOR
FORMING LONG AND COMPLEX MOLECULES IS:
________________________________________________________________________________________________
REASON NUMBER 4:
1. Using your model make a chain with four carbon atoms.
a. How many more atoms can you attach to your model?
b. Try attaching different combinations of different kinds of atoms to
see how many different molecules you can make?
FUNCTIONAL GROUPS (HONORS ONLY)
A. Click on the link below:
http://www.phschool.com/science/biology_place/biocoach/biokit/function.html
a.
b.
c.
d.
e.
Define functional group
Click on each of the functional group links and fill in functional group matrix
Click on practice and perform
Click on challenge and perform
Take self quiz
B. Functional groups are specific groups of atoms that attach to the carbon
backbone that gives the molecule specific characteristics.
a. Using your model create a four-carbon backbone, add oxygen to
the last carbon and then add hydrogen to the oxygen. This OH
attached to the carbon is a functional group called a
______________________________.
b. Now take a new carbon atom and connect it with two bonds to
oxygen. Connect another oxygen to this new carbon atom and then
add hydrogen to the carbon. This is another functional group
called a ____________________ Attached this group to your four-carbon
backbone.
c. Obtain a nitrogen atom and connect two hydrogen atoms to it. This
functional group is called an ________________. Attach this group to
your four-carbon backbone.
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C. Each functional group gives different properties to the molecule.
a. Carboxyl groups make molecules polar and act as acids (donate
hydrogen ions to solution)
b. Hydroxyl groups make molecules polar (hydrophilic and soluble)
c. Amine groups make molecules act as a base (take hydrogen ions
out of solution)
D. Identify the functional groups below by circling and labeling:
REVIEW:
1. There are millions of organic molecules. What element has unique properties
to be able to make so many different types of molecules?
2. Explain why the element you chose in question 1 is able to make so many
different types of organic molecules.
GOING FURTHER:
1. If cells and thus living things are made of organic molecules and cells make
these molecules themselves. Where and how do cells obtain this unique
element you chose in question 1 of a review?
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