Students will watch the introductory video clip that provides a visual animation of the protein synthesis process.
After the video, students will use the video clip, their Lecture Notes - Protein Synthesis from a previous lesson, and the textbook to create a simplified summary of protein synthesis. This basic explanation will serve as a foundation for a more developed explanation that the students will write later in the lesson.
Students will share there short narrative pieces with their neighbor. The teacher will ask for volunteers to explain the processes of transcription and translation to the class. The teacher will review additional details of protein synthesis in the next section of the lesson to clarify student understanding.
Sample of Student Video Notes - These two student work samples show the variation of depth and details that students use when asked to record video notes in class.
Students have already taken Lecture Notes and have been introduced to the processes of protein synthesis (transcription and translation) in a previous lesson. Due to the complexity of the process and the need for students to follow the transition from DNA to mRNA (transcription) to a protein chain (translation) it is vital to reinforce this content in multiple lessons.
The teacher will review the processes in the front of the room in a whole-group discussion with step-by-step details. Students are encouraged to ask for clarification at any time! If you have models of DNA to serve as manipulatives, it will support the students' ability to visualize this multi-step process.
Sample Analogy to Conceptualize Translation: My students were struggling to conceptualize how mRNA was translated into the amino acid and how the amino acids join together to form a protein chain. An effective analogy for my students was to compare the ribosome (made of ribosomal RNA) to a conveyor belt at the grocery store. The mRNA arrives at the ribosome (the conveyor belt) and there is a imaginary "scanner" at on end like the grocery store. The mRNA sequence moves along the conveyor belt and the "scanner" will read the mRNA codons in three letter increments like the grocery store reads the bar code on the groceries. Then transfer RNA will match up the complimentary anticodon with the messenger RNA's codon so that the correct amino acid is delivered to the "conveyor belt" (ribsome). Once the amino acid has been delivered then the mRNA strand moves forward so the next codon can be read by the "scanner". The process continues until the "scanner" reads a "stop" codon message on the mRNA. The covalently-bonded amino acid chain has now created a protein which is released so that it can complete its specific function in the cell.
Each student will receive a Protein Synthesis With A Bling Handout that will guide them through this hands-on simulation of protein synthesis.
Step #1: Students will select a type of protein bracelet to create from one of the six categories that represent each of the six specific functions of proteins in our cells:
Step #2: Students will transfer the sequence of amino acids into the data table on the activity handout.
Step #3: Students will use the Universal Genetic Code from their textbooks to determine the mRNA codon that is associated with each amino acid that was provided to represent their selected bracelet. This process is the backwards process of translation which usually goes from the mRNA codon to amino acid.
Step #4: Students will use the mRNA codon to "backwards" trancribe the mRNA into the corresponding DNA sequence. Keep in mind that the process of transcription usually goes from the original DNA sequence to create the complementary mRNA sequence.
Step #5: Once the data table has been completed, students need to use their handout to select the correct bead color that represents the amino acid that is associated with their "protein" bracelet.
Step #6: Create the "protein" bracelet
Step #7: Respond to the conclusion questions on the activity handout.
Sample Student Bracelet - Each color bead corresponds to the correct amino acid that was described in the selected "protein" bracelet that the student selected.
Sample of Student Work #1 - This student did a nice job completing the data table to demonstrate the processes of transcription and translation.
Sample of Student Work #2 - This student did a nice job completing the data table to demonstrate the processes of transcription and translation, as well as the conclusion questions. This sample requires that the teacher review the discussion questions with the class to ensure all students can transfer their understanding of transcription, translation, and proteins to real life applications.
Student Video Clip - This student will describe the benefits of this activity and goes into great detail to discuss the process of transcription and translation.
As a lesson wrap-up, students will complete a one-minute report that details how the structure of DNA will determine the structure and function of which protein is created.