A WebQuest designed by Suzanne Reed

And Dana Kwiatkowski

Breaking the Code

• The Topic • The Task• The Process• The Resources• The Evaluation

The TopicScientists Watson and Crick determined the 3-D structure of DNA in the 1953. A few years later, Marshall Niremberg broke the code contained in the 4 letter alphabet of DNA. We now know that DNA is made of 4 types of nitrogen bases called:

• Adenine

• Guanine

• Cytosine

• Thymine

Each base is represented by its first letter, as a letter of the DNA alphabet.

For example:

• Adenine is represented by

A• Guanine is represented by

G• Thymine is represented by

T• Cytosine is represented by

C

Each of these letters is a part of the code that tells the cells what order to put amino acids in as the cell builds new proteins. Next to DNA, proteins are the most important molecules in

our cells. DNA tells the cell which proteins to make, then proteins do the “work” of cells.

The Task

Your group will work together to build a three dimensional model of DNA using any materials of your choice. The model will have to have the correct number of bases and the bases must be in the correct sequence. You will determine the sequence as you

The Process

This project can be done as an individual or in a group. The only product an individual has to turn in is the model itself. If done as a group project, then the task will be divided into 4 jobs. Pick the job below that you are interested in completing.• Research Scientist (Group of 1, 2, 3, or 4 people)• Artistic Consultant (Group of 2, 3, or 4 people)• Building Supervisor (Group of 3 or 4 people)• Purchasing Agent (Group of 4 people)

Your group will all be responsible for the final model, butyour job gives you specific tasks that you will be held accountable for.

Research Scientist

Your job as the research scientist is to examine the sequence of amino acids on the next page and determine the sequence of bases it represents. You will need to use your text and the following websites:

http://www.johnkyrk.com/DNAanatomy.html

http://www.biology.clc.uc.edu/courses/bio104/dna.htm

In addition to research, you will submit a one page typed report that describes DNA. Your report should explain how the bases code for the amino acids.

Back to The Process

2008 Sequence of Amino Acids

• Start codon• Leucine• Glutamine• Lysine• Alanine • Arginine• Stop codon• Back to The Process

Purchasing Agent

• You will need to develop a list of possible materials and the costs of these materials for your group.

• Once the group has decided on materials, you will collect money for the materials and purchase the materials.

• You will submit a one page report of the materials you choose, how much the materials costs, and if you would recommend these materials in the future and why or why not. Your report should explain what materials were used to form each of the parts of DNA.

• Back to The Process

•

Artistic Consultant

You will work closely with the purchasing director to decide on possible materials for the model. You will also draw and submit a color schematic of what your model will look like. The drawing should be labeled and completed before you

build your model. It is your “blueprint” for construction. You will turn in your drawing and a description of each part.

Back to The Process

Building Supervisor• Your primary job is to plan the

construction phase of the model building.• You will determine when and where

assembly will take place and distribute labor equally among other group members.

• You will turn in a typed chart of when you worked on the model, how long you worked, where it was done, and which members were present. Each of the members needs to sign the chart to verify their efforts.

• You should also write a description of what materials were used for each of the parts of the model.

• Back to The Process

The Resources

• There are several biology texts available in the classroom in addition to your text that will be helpful

• Sample models of former students will be available for your inspection• Check the following websites on DNA:

http://www.ncc.gmu.edu/dna/

http://www.pbs.org/wgbh/aso/tryit/dna/

http://www.johnkyrk.com/DNAanatomy.html

http://www.biology.clc.uc.edu/courses/bio104/dna.htm

http://web.indstate.edu/thcme/mwking/protein-synthesis. html#genetic%20code

The Evaluation

• The Report from each job:

Each position will file a typed, one page report of their activities and include any drawings requested in the instructions. The report should have the job title and the name of the individual assigned to that job.20 points per report —to impact your grade only—not the group grade

The Model

Double Helix (must make a minimum360 degree turn) 15 pointsAccurately bonds phosphates, sugars and bases 10 pointsCorrectly pairs bases 10 pointsBases are properly sequenced according to code 35 pointsKey is provided and legible 10 points

80 points

Report/Drawing/Chart 20 points

Due Dates

• November 28—First Period

• November 29—Fifth Period

• November 30—Sixth and Seventh Period• The projects are due at the beginning of class. If

turned in later than the beginning of class, the grade will be reduced by one letter grade. Each day thereafter will be a letter grade reduction.

Conclusion

The discovery of the shape of DNA and the code it contains was one of the most important

breakthroughs of the last century. Be prepared to share with the class how your understanding of

DNA has grown as a result of