Beacon Lesson Plan Library

Constructing a Protein Sentence

Barry Anderson
Orange County Schools

Description

Students will utilize their knowledge of RNA transcription and translation in order to make a protein. They will use a DNA template (portion of the DNA that will code for the protein) to determine the m-RNA and t-RNA sequences for that protein.

Standards

Florida Sunshine State Standards
SC.F.2.4.2
The student knows that every cell contains a `blueprint` coded in DNA molecules that specify how proteins are assembled to regulate cells.

Florida Process Standards
Critical and Creative Thinkers
04 Florida students use creative thinking skills to generate new ideas, make the best decision, recognize and solve problems through reasoning, interpret symbolic data, and develop efficient techniques for lifelong learning.

Materials

Note: All of the following materials can be located in the attached files at the end of this lesson plan.

-Student review sheet and instructions Constructing a Protein Sentence, one for each student
-Data Sheets (Each data sheet has enough space for analyzing two DNA templates. Two data sheets will be required per paired group.)
-Anti-codon Words (Each paired group should receive this handout.)
-17 DNA templates (The best approach for these templates is to keep them away from the students. The instructor should be the only one passing out these templates. There are seventeen different templates. I suggest that the instructor make four to five copies of each template, depending upon the number of students in the class. Once the copies are made, they should be cut into strips so that the individual templates can be given to each pair of students. Try not to give the same template to student groups that are next to each other in the room.)
-Pen or pencil

Preparations

1. Each student should receive a copy of the student review sheet and instructions Constructing a Protein Sentence. (See attached file.)
2. Each data sheet has enough space for analyzing two DNA templates. Two data sheets will be required per paired group.
3. Each paired group should receive the handout on Anti-codon Words. (See attached file.)
4. There are seventeen different DNA templates. The best approach for these templates is to keep them away from the students. The instructor should be the only one passing out these templates. I suggest that the instructor make four to five copies of each template, depending upon the number of students in the class. Once the copies are made, they should be cut into strips so that the individual templates can be given to each pair of students. Try not to give the same template to student groups that are next to each other in the room. (See attached file.)

Procedures

Note #1: It is imperative that the instructor emphasizes to the students that they will be using higher levels of learning in this exercise. Each student will be using the following skills.

Creative thinking skills:
(a) Show the class a textbook diagram or flow chart of the steps that are involved in making a protein.
(b) Emphasize that they will have to understand the sequences of nitrogen bases and how they are complementary to each other when considering the DNA template, m-RNA and t-RNA.
(c) Stress the importance of (b) since they will have to put on their thinking caps in order to accomplish the goals of the lesson.

Recognizing and solving problems through reasoning:
(a) Explain to the class that the examples you have shown them are similar to the DNA templates that they will be using in their lesson.
(b) Emphasize that once they can recognize the similarity, they should be able to reason out the new sequences of m-RNA and t-RNA.

Making the best decisions on the basis of their knowledge:
(a) Tell the students that with the background that they have had through your previous lessons and the review they will be having prior to the lab, they will be ready to perform the task on the basis of this knowledge.

Note #2: In order for the students to complete the activity, they will have had previous instruction and knowledge concerning the process of transcription and translation. Students will have access to the following review information (see attached attached file) in a handout titled Constructing a Protein Sentence.

(a) When DNA nucleotides pair with RNA nucleotides, they do so in the following manner:

ADENINE (in DNA) pairs with URACIL (A-U) in the RNA molecule.
THYMINE (in DNA) pairs with ADENINE (T- A) in the RNA molecule.
CYTOSINE(in DNA) pairs with GUANINE (C-G) in the RNA molecule.
GUANINE (in DNA) pairs with CYTOSINE (G-C) in the RNA molecule.

(b) Recall that tRNA pairs with mRNA to translate the message. Therefore, you will NOT be making any base pairs with THYMINE.


SESSION 1

1. Review the following terms with the students before beginning this activity: DNA, tRNA, mRNA, nucleotide, triplet, codon, anti-codon, amino acid, transcription, and translation.

2. Handout the review sheet to each student and lead them in a class discussion of the terms included on the sheet. In order to continue with the lesson, an understanding of these terms is necessary.

3. Explain to the students that they will work in pairs to apply what they have learned about transcription and translation in the process of protein synthesis. Hand out copies of the handouts Data Sheets and Anti-codon Words (see attached attached files) to each pair of students. Go over the information and directions with the students to be sure that they understand the task. The handouts in the attached files include the specific information on the activity.

4. Tell the students that the main object of this lesson is to understand the concepts governing the mechanisms of protein synthesis. Explain to the students that instead of learning the names of the amino acids that go into making a protein, they will substitute words for amino acids. Inform the students that these words will eventually form a logical sentence (protein) about biology and the processes involved in protein synthesis. Show the students that the correct linear order of the amino acids determines the proper functioning of the protein; hence, if the students understand the concepts of transcription and translation, they will end up with a sentence that is grammatically correct.

5. Hand out one DNA template (see attached attached file DNA templates) to each pair of students. Instruct the students to write the template sequence in the space provided on the data sheet. Instruct the students to leave a small space between each triplet (in order to be more readable) and place the number of the template (there are 17 different templates to choose) in the space provided at the top of the data sheet.

6. Inform the students that they are to transcribe the DNA template into mRNA and record the mRNA sequence of codons in the space provided on the data sheet.

7. Let the students know that they must record the tRNA sequence of anti-codons in the space provided on the data sheet.

8. Relate to the students that once they have determined the tRNA sequence of anti-codons, they will use the anti-codon word list to find the proper match of anti-codons and words.

9. Direct the students to record the message in the space provided on the data sheet.

10. Explain to the students that if the protein' has been properly constructed, they will end up with a coherent message. If not, they will end up with a nonsense message.

11. Require the students to show their instructor the word sequence.

12. Inform the students that if the word sequence is incorrect, they must repeat the process using the same DNA template. If the word sequence is correct, they will be given two more DNA templates, which can be analyzed during session 2.

SESSION 2

1. Start this session with a quick review on what was accomplished during session one.

2. Review with the students the procedures followed the day before.

3. Require the students to analyze two additional (different) DNA templates.

Assessments

Students will utilize DNA templates to formulate the codons for the m-RNA strand, followed by formulating the anti-codons for the t-RNA strand, and finally using an anti-codon decoder to determine the sequence of the amino acids in the protein.

Students will use a data sheet for each of the proteins that they will be making. All codons, anti-codons, and amino acid sequences of the proteins will be checked for accuracy.

Immediate feedback will be a key issue. When the students are not generating the proper sequence of amino acids, there will be assistance on the part of the instructor to direct them toward that goal. Feedback will be continuous until the students have made the protein. Once the students have made one protein, they will be directed to make at least two additional proteins. The second and third proteins made will be graded as correct or incorrect.

Extensions

The number of sentences in this lesson plan can be increased so that the instructor has more than the seventeen that I have included in this plan. The instructor can rearrange some of the words to make new sentences. In addition, one could also make new words by combining some of the words to use only one transfer RNA anti-codon. For instance, combine a and an by using the following a(n). This would eliminate one of the anticodons and thus give you one more anticodon for one new word. Another example would be to use one anti-codon for the words form and formed making the term as follows: form(ed). Other words to combine could be gene and genes, acid and acids, molecule and molecules, code and codes, and protein and proteins.

As usual with special needs students, you will have to spend more time with them and give them extra time to complete the assignment.

Attached Files

Anti-codon Words     File Extension:  pdf

Answer Key for Protein Sentences     File Extension:  pdf

DNA Templates     File Extension:  pdf

Procedures for Constructing a Protein Sentence and Data Sheets     File Extension:  pdf
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