Bio H - Biochemistry
BUILDING ORGANIC MOLECULES
For each molecule below you are going to a) answer the questions, b) draw the skeleton form of the molecule and then
c) build the molecule using the kit.
How to build models:
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Each different color represents a different element. The holes in each atom will tell you how many bonds that atom
can form. For our purposes today, these atoms only form compounds that fill all of their valence spots. So, if you
have open holes in your molecule, you have done something wrong!
o Look for an atom that has 4 legs – these represent the fact that this atom has 4 electrons in the outer shell
(and wants to fill that shell
o Look for another atom that has 2 legs – this means this atom has 6 electrons in the outer shell and wants to
bond (share 2 electrons from some other atom)
o Finally there are smaller atoms that have only a single leg. That indicates that they want to fill their first
orbital (they can only have 2 electrons, total.
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There are two types of bonds available (but right now you only have one type). The longer flexible bonds are to be
used only for DOUBLE bonds: bonds where two atoms are sharing two pairs of electrons (you will use two of these
longer bonds to create a double bond. Double bonds are on Mrs. Landa’s desk. The shorter inflexible bonds are for
SINGLE bonds: bonds where two atoms share a single pair of electrons. You have only single bonds.
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Remember that carbon has many unique shapes that it can form!
Introduction: Use the following questions to review the basics we just talked about.
1.
IN YOUR WORDS, what is the difference between an organic molecule and a hydrocarbon?
2. What chemical property of Carbon makes it so special?
3.
Draw an example of each of the following: BE NEAT, you may use skeleton drawings
a. Carbon can bond 4 other atoms:
b. Carbon can form double bonds:
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Bio H - Biochemistry
c. Carbon can form branching molecules:
d. Carbon can form rings:
4. What two types of atoms can be
“hidden” in the skeletal structures?
Skeletal Structure Remember: You can hide all C’s, H’s and
C-H bonds. BUT you must show C-C bonds, double bonds
and all other atoms!!
Molecule 1:
a. Chemical formula: ________________________
b. Build the model and have me check off here: ______________________
Molecule 2:
Skeletal Structure:
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Bio H - Biochemistry
a. Chemical formula: ________________________
b. Build the model and have me check off here: ______________________
c. Skeltal structure
Molecule 3 (you will need the other type of kit):
Skeletal Structure:
a. Chemical formula:
________________________
b. Build the model and have me check off here: ______________________
Molecule 4:
The carbon on the right side is carbon 1. Go clockwise and you will see carbon 2,
3 and 4. Carbon 6 is not in the ring, and is connected to carbon 5. Note the H
and OH “groups” coming off of C1-C4. The OH group is DOWN on the first and
second carbons, up on the 3rd and down on the fourth. DOWN DOWN UP DOWN
Skeletal Structure:
a. Chemical formula: ________________________
b. Build the model and have me check off here: ______________________
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Bio H - Biochemistry
Molecule 5:
Skeletal Structure:
a. Chemical formula: ___________________
b. Build the model and have me check off here: ______________________
Finally: Looking at molecule 5, note the two hydrogen atoms bonding to the carbons on either side of the carbon-carbon
double bond. What would happen to the molecule if you move ONE of the hydrogens to the OTHER side of the carbons.
You may have to break and re-form part of the carbon-carbon double bond. Try it and see what happens. Call me over
when you think you can see any changes!
WHAT IS THE CHANGE?
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