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Protein Synthesis and Words
From Access Excellence by Lynn Marie Wartskind
Modified by Kirstin Bittel and Rachel Hughes

Time: 1 class period
Preparation Time: 5-10 minutes photocopying cards
10-15 minutes cutting out cards
Materials: 20 DNA Template Cards
64 Anti-Codon Cards (folded so words are not visible until the cards are picked up)
Protein Synthesis Overhead
Protein Synthesis and Words Answer Key

 


Abstract
During this lesson students learn about the roles of the mRNA, ribosomes, tRNA and how the cells synthesize proteins. Students simulate parts of a cell to learn about the process of protein synthesis.


Objectives
Students will be able to:-
1. Explain the roles of mRNA, tRNA and ribosomes.
2. Explain how mutations can occur in an individual.

National Science Education Standard
Content Area C – The Cell
- Cells have particular structures that underlie their functions. Every cell is surrounded by a membrane that separates it from the outside world. Inside the cell is a concentrated mixture of thousands of different molecules which form a variety of specialized structures that carry out such cell functions as energy production, transport of molecules, waste disposal, synthesis of new molecules, and the storage of genetic material.

- Cells store and use information to guide their functions. The genetic information stored in DNA is used to direct the synthesis of the thousands of proteins that each cell requires.

- Cell functions are regulated. Regulation occurs both through changes in the activity of the functions performed by proteins and through the selective expression of individual genes. This regulation allows cells to respond to their environment and to control and coordinate cell growth and division.


Content Area C - The Molecular Basis Of Heredity
- In all organisms, the instructions for specifying the characteristics of the organism are carried in DNA, a large polymer formed from subunits of four kinds (A, G, C, and T). The chemical and structural properties of DNA explain how the genetic information that underlies heredity is both encoded in genes (as a string of molecular "letters") and replicated (by a templating mechanism). Each DNA molecule in a cell forms a single chromosome

- Changes in DNA (mutations) occur spontaneously at low rates. Some of these changes make no difference to the organism, whereas others can change cells and organisms. Only mutations in germ cells can create the variation that changes an organism's offspring


Teacher Background


Related and Resource Websites

http://www.accessexcellence.org/AE/ATG/data/released/0247-LynnWartski/index.html
http://www.accessexcellence.org/AB/GG/protein_synthesis.html
http://gslc.genetics.utah.edu/units/basics/transcribe/

 

 

Activity
Engage (How do you think mutations occur at the individual level? How do you think these mutations might affect us as individuals?)
1. As students enter the room, assign them the roles of mRNA, tRNA, ribosome. Have the DNA cards taped to the front board and labeled NUCLEUS. Have the anti-codon cards on a table in another part of the room. Cards can be lumped together or spaced out by the initial letter on each anti-codon card.
2. Ask students to think back to their study of the cell. Ask for volunteers to remind the class about the function of the mRNA, tRNA, and ribosomes.
3. Tell students, “Today we will be simulating the synthesis of proteins. You will be in groups of three. Each group will need one mRNA, one tRNA, and one ribosome. Together, your group will compete against the others to try to correctly transcribe and translate as many proteins as possible. Since the DNA is located in the nucleus, the DNA cards must remain on the board. The student simulating the mRNA will come to the board, read the DNA code, and encode into RNA. (Remember that there is no T in RNA) The strips of code written by the mRNA will be passed to the ribosome. The ribosome will then read the RNA and write the anti-codons. (Remember that there is no T in RNA). Once the ribosome has done its job, the strip is passed to the tRNA. The tRNA will go to the anti-codon cards and search out the words (proteins) that correspond to the anti-codons. The tRNA will then bring the protein to me. If correct, the team gets a point, if not, they must begin again. (Remember that all sentences begin with the start (AUG) and end with the stop (TAG) codon. Good Luck.”
4. Allow students sufficient time to translate and transcribe several “sentences.” Students will bring you incorrect/mutated sentences. These are wonderful examples of mutations and should be saved to discuss at the end of class.
5. Bring the students back together. Ask students “What were the challenges that faced each person? Where were mistakes or potential for mistakes made?”
6. Ask students, “When we are talking about errors in DNA, and protein synthesis, what do we call mistakes? [Mutations] Are these mutations going to affect individuals or the entire species? [Individuals] Why? [Because the mistakes occurred during translation and transcription, not during the creation of haploid (sex) cells]

Embedded Assessment

 


PULSE is a project of the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center and is funded by:


an
NIH/NCRR award #16260-01A1
The Community Outreach and Education Program is part of the Southwest Environmental Health Sciences Center: an NIEHS Award

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Supported by NIEHS grant # ES06694


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Last update: November 10, 2009
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