Download DNA Structure and Lab

Name______________________
Box #: ______
Period: ______
DNA Structure and Lab
#5
SIDES:
-deoxyribose D (a type of sugar)
-phosphate P
RUNGS:
-adenine A
-thymine T
-guanine G
-cytosine C
-hydrogen bond H
The structure of DNA (p. 101)
DNA is also called:
The sides are made of:
The rungs are made of:
There are 4 nitrogen bases: ____________________ (A)
____________________ (T)
____________________ (G)
Pair together
Pair together
____________________ (C)
The Genetic Code (p. 132)
DNA makes up _____________.
Genes control _____________________________________________________________________
The order of _________________ bases along a gene forms a __________________ code that
specifies what type of _______________ will be produced.
Each ____________ is located in a specific spot on a specific ____________________.
If a sequence of nitrogen bases is A-T-G-A-C-G-T-A-C, what are the corresponding nitrogen bases?
1. State the problem or question.
What do you think DNA will look like without a microscope?
2. Form a testable hypothesis.
I think the DNA will look like…
3. Design an experiment
1. In one Dixie cup, your teacher will add about 20mL of a salt water solution. Record
observations in table. Put it in your mouth and swish it around for a few seconds. Do not
swallow it! Spit the salt water solution back into your Dixie cup.
2. Pour your salt water solution into a test tube. The test tubes are filled with water and dishwashing
liquid. Record observations in table.
3. Place your thumb over the top of the test tube and GENTLY rock the tube back and forth for a
couple (2) minutes. Record observations in table.
4. Ask your teacher to add a teaspoon of rubbing alcohol to the test tube and let it sit for a few
minutes (about 5). Record observations in table.
5. You should see the DNA separate out. If you want, you many use a toothpick to pull the DNA out
of the cup. If you want to take it home, see your teacher for a Petri dish.
4. Collect and analyze data
Complete the following chart as you are working.
Step
Observations
Salt water before going into
your mouth
Salt water after adding to the
test tube
Test tube after rocking it back
and forth for 2 minutes
Test tube after adding rubbing
alcohol
5. Draw conclusions.
1. How do you think the DNA got out of the cell?
2. What are the sides of the DNA ladder made of?
3. What are the rungs of the DNA ladder made of?
4. How do the nitrogen bases pair with each other? (What nitrogen bases pair together?)
6. Communicate results
Color the DNA molecule on front according to directions (on screen in classroom). Turn this in and
when you get home tell your parents what you saw today!