Message in a Ladder?

A WebQuest for 11th Grade (Biology)

jmkohne@indiana.edu

Introduction

It is the year 2153, the Earth has been invaded by a race of machines called the Mechabots. The Mechabots roam the galaxy using up planetary resources and destroying every biological life form they encounter.

You are a member of an underground resistance force, Earth’s last chance at survival. The overwhelming forces of the Mechabots have force your forces to scatter across the globe. Communications must be coded in order for your efforts to remain secret from the evil machines; however the Mechabots have been able to break almost every code used thus far. However, there is one code the Mechabots have never been able to break. The code uses a language that the Mechabots have never been able to understand—genetic code.

A scientist in your group has discovered the one weakness of the Mechabots and the salvation of our planet. The message must be sent out to all the resistance groups. The Mechabots are making their final assault on all life in 2 hours. As the holder of the secret that will free the planet, you must code the message and send it before it is too late.

Task

Using all the resources at your disposal:

Encode the secret message and deliver it to your commanding officer before time runs out;
Provide a key to the code, so that your commanding officer can verify the message before the end of the period.

Process

You have been assigned a partner to accomplish this mission. Before you start, you need to know the secret to the destruction of the Mechabots:

“CITRIC ACID MELTS THEIR WIRING”

You must use the genetic code to create a small strand of DNA which can be transmitted to the other resistance groups around the world. You have never used this code before. You have been given two clues.

· Each letter of the message corresponds to the single letter abbreviation of one of the 20 natural amino acids (i.e. C=Cys=Cysteine).

· Remember you are performing the steps of all the processes you are learning in reverse of how they work in nature.

You will need to understand the genetic code. First use the following resource site to learn about the amino acids and their properties:

http://www.vivo.colostate.edu/hbooks/molecules/aminoacids.html

Using what you have learned write down in your lab notebook the amino acid sequence that would spell out the secret message.

Next you will need to understand how to change your amino acid sequence to a strand of mRNA. Use these resource sites to learn more about the genetic code and protein translation:

http://library.thinkquest.org/18617/data/synthesis/translation.html#initiation

http://www.wisc-online.com/objects/index_tj.asp?objid=AP1302

Now write down in your lab notebook the definition of protein translation and the mRNA sequence that corresponds to your amino acid sequence. Don’t forget to add start and stop signals and remember to use 5’ to 3’ orientation.

Finally, you need to convert your mRNA sequence to DNA for transmission to your commanding officer. Use this resource site to learn about DNA transcription:

http://www.agresearch.co.nz/scied/search/molecular/dnatranscription.htm

http://en.wikipedia.org/wiki/Transcription_(genetics)

In your lab notebook, write down the definition of transcription and the DNA sequence that could be used to create the amino acid sequence that spells out the secret message (don’t forget 5’ to 3’ orientation).

Deliver your notebook to your commanding officer for message transmission and verification.

Evaluation

Describe to the learners how their performance will be evaluated. Specify whether there will be a common grade for group work vs. individual grades. You may want to have separate rubrics for individual and group work.

	Developing 0	Accomplished 2	Exemplary 4	Score
Amino Acid Sequence	Incorrect Amino Acid Sequence	Description of identifiable performance characteristics reflecting mastery of performance.	Complete and accurate Amino Acid Sequence
mRNA Sequence	Incorrect mRNA Sequence	Correct mRNA sequence but lacking proper start/stop codons and orientation	Complete and accurate mRNA sequence based on your Amino Acid Sequence with proper start/stop codons
DNA Sequence	Incorrect DNA Sequence	Correct DNA sequence but lacking proper orientation	Complete and accurate DNA sequence based on your Amino Acid Sequence

Conclusion

You have encoded the secret message; hopefully it is the correct one. Resistance forces around the world are putting to use what you have told them. Ask your commanding officer if your mission was a success.

You have learned much about the genetic code. Every second, DNA in your body, and in every living thing, goes through the process you have learned about. DNA is transcribed to mRNA and then translated to a sequence of amino acids or protein.

How else has the genetic code been used to save lives in our time? Take a look at this site if you are interested in learning more:

http://news.nationalgeographic.com/news/2005/10/1026_051026_dna_hapmap.html

Credits & References

I would like to thank http://www.fotosearch.com/clip-art/helix.html for use of the double helix clip art at the top of the webquest.

Also, I would like to give credit for the webquest template and layot design to The WebQuest Page (http://webquest.sdsu.edu/). It is a great source of templates and training for webquests.