Course Title:
Advanced Plant and Soil Science
Lesson Title:
Transcription and Translation
TEKS Addressed in Lesson: 130.21(c)(15)(A)
http://www.tea.state.tx.us/index2.aspx?id=5415#Subchapter A
Lesson Objectives: The student will be able to:
1. Demonstrate their understanding of protein synthesis by becoming a DNA molecule,
mRNA molecule, and tRNA molecules.
2. Demonstrate the construction of a protein.
Tools and Equipment






baby plastic snap beads
baby plastic snap stars
detachable DNA plastic model, (free nucleotides)
signs with yarn labeled DNA, mRNA, 2tRNA and 2 amino acids
genetic code circle and questions
YouTube video http://www.youtube.com/watch?v=W4mYwsr9gGE&feature=related
Key Terms / Vocabulary
transcription
uracil
translation
protein synthesis
Interest Approach/Anticipatory Set
Several questions should be asked to help the students start thinking about protein synthesis
including transcription and translation.
1. How is the information in the DNA use to control the functions of the cell?
2. What are the roles of RNA in this process?
Teaching Plan and Strategy / Presentation of New Material
1. Present new material in the you tube video entitled “DNA and RNA : Part 2”
http://www.youtube.com/watch?v=W4mYwsr9gGE&feature=related
Activity/Application/ Student Engagement /Laboratory
1. In a class of 30 have 16 students become a DNA molecule with the sequence
CAGACTTA and its complimentary code of GTCTGAAT as in the previous activity
(green/adenine, yellow/thymine, blue/guanine, and red/cytosine). Then have 6 students be
complimentary mRNA nucleotides for the middle six nitrogen bases of the CAGACTTA
side of the DNA molecule. The complimentary strand of mRNA will be UCUGAA with
the purple snap bead for the nitrogen base uracil. Next have 6 students become the anticodon for the two codons of the messenger RNA sequence with will be read off the
DNA. They should have the sequences AGA and CUU. Finally have two students
become amino acids that will attach to the transfer RNA with the anti codon of AGA
(serine) and CUU (glutamic acid). If you have smaller classes have the DNA chain
become one pair of nucleotides shorter and substitute plastic stars for the students who
were the amino acids.
2. Once the roles have been assigned, the students of the DNA molecule should arrange
themselves in the proper sequence. Have the complimentary base pairs match up to form
the double strand of the DNA molecule. Next in transcription, now have the DNA strand
unzip its six middle nitrogen base pairs. The teacher can act as the protein, RNA
polymerase, which helps in the unzipping of the DNA molecule. The free mRNA
nucleotides should match up with the complimentary nitrogen bases of the AGACTT side
on the unzipped section of the DNA molecule. The teacher can now become the protein
which helps the free nucleotides match up followed by becoming the protein, ligase,
which connects the sugar and phosphates along the side of the mRNA single strand. If
you do not become the proteins then you should have the student match up and then form
the covalent bonds on their own. Now have the students unzip the strand of mRNA from
the DNA and leave the nucleus. The DNA may then re-zip to form the double strand.
3. Now have the students which became the mRNA move out into the cytoplasm of the cell
and attach to a desk or counter which represents the ribosome. The translation of the
mRNA will now begin. The students which represent the tRNA must have the
complementary sequence to match up with the mRNA on the ribosome. Before they
move to the mRNA they must pick up the correct amino acid which is one of the
students. They can use the genetic code circle to determine which amino acid they pick
up. The students who are the amino acids may wear a tag which labels the amino acid
that they are to enable the tRNA to match up. After the two tRNA sequences have
attached to their amino acid by holding hands they need to move to the mRNA and match
up their anti-codon with the codon. Now they need to snap their beads together. The
second tRNA will then come in and repeat the sequence that the first tRNA did. Then the
two amino acids will connect at the elbow to symbolize the polypeptide bond. Finally, the
first tRNA will leave. This will complete the simulation with the beginning of the protein.
The teacher should ask the students what will happen next in the production of a
continuing chain of amino acids.
Evaluation / Summary
Have the students write a paragraph describing roles of DNA and RNA in the production of a
protein or you can have the students complete the questions on the genetic code circle sheet.
References/Additional Materials / Extended Learning Opportunities/ Enrichment
Postlethwait, John H. and Hopson, Janet L., et al. Modern Biology. 2nd ed. Austin, TX: Holt,
Rinehart and Winston, 2009.
Campbell, Neil A., Reece, Jane B. and Mitchell, Lawrence G., et al Biology. 9th ed. Menlo Park,
CA: Pearson, Benjamin Cummings, 2010
College & Career Readiness Standard:
Science VI D3
©Texas Education Agency, 2011