Name: _____________________________ Date: _____________________ Biology The Great Protein Synthesis Race – Express Yourself!! A gene directs the synthesis of a protein by a two-step process. First, the instructions in the gene in the DNA are copied into a messenger RNA (mRNA) molecule. The sequence of nucleotides in the gene determines the sequence of nucleotides in the mRNA. This step is called transcription. Second, the instructions in the messenger RNA are used by ribosomes to insert the correct amino acids in the correct sequence to form the protein coded for by that gene. The sequence of nucleotides in the mRNA determines the sequence of amino acids in the protein. This step is called translation. If needed, rewatch this video on how a gene used to make a protein: From DNA to Protein. (We watched this one in class.) In this activity, you’ll be “race” to simulate the processes of protein synthesis, while learning about transcription and translation as you build a protein the same way that a real cell does! Open the simulator at BioManBio and work through the game. Be sure to read all of the text and instructions before you move past the end of each step! Part 1: TRANSCRIPTION 1. Transcription is the copying of a _________ (section of DNA). 2. Look at the DNA on the screen. Which nitrogen bases (found in nucleotides) match up to make the rungs of the DNA ladder? a. T pairs with _____ b. C pairs with _____ c. A pairs with _____ d. G pairs with _____ 3. For transcription to occur, DNA must ____________. 4. The enzyme ____________ is used to add new RNA nucleotides to make RNA. (Hint: it’s pink!) 5. As you transcribe the gene, notice: which bases pair up? a. T pairs with ___ b. C pairs with ___ c. A pairs with ___ d. G pairs with ___ 6. What was your time required for transcription? What was your percent accuracy? 7. What type of biomolecule polymer are both DNA and RNA? (Remember, there are only 4 types of biomolecules…) ____________ 8. What are the monomers that are used to build DNA and RNA? ____________ 9. Compare and contrast DNA replication and transcription in the table below: DNA replication Transcription A whole chromosome is replicated. ___________________ is transcribed. DNA is made. DNA is double-stranded. mRNA is made. mRNA is _____________ stranded. DNA nucleotides are added to the growing DNA chains. _____ nucleotides are added to the growing RNA chain. DNA polymerase is the enzyme which carries out DNA replication. __________ is the enzyme which carries out transcription. T = thymine is used in DNA, so A pairs with T in DNA. T = thymine is replaced by ______ in RNA, so A in DNA pairs with ___ in mRNA. Bonus: DNA nucleotides contain the sugar __________ Bonus: RNA nucleotides contain the sugar __________ 10. When the transcription is complete, the mRNA is released from the DNA and moves to the _______________, the site of protein synthesis. (For the game, use the directional keys/arrows to move the mRNA down and out of the nucleus.) Recap of Transcription: 11. Summarize transcription by explaining how a gene directs the synthesis of an mRNA molecule. Use the word bank and sentence frames below, or write your own sentences. Word Bank: base-pairing rule cytoplasm gene nucleotide complementary DNA messenger RNA nucleus RNA polymerase First, _____, then _____, lastly… Initially, _____, meanwhile _____, finally... Prior to, _____, followed by _____, eventually... To check your understanding, complete the embedded quiz inside the simulator. 12. What is the function of mRNA? ____________ functions to ____________. 13. What happens to the DNA after transcription? When _____, then... As _____, meanwhile _____, finally... Following _____, _____, then_____… Adapted from original materials: “Protein Synthesis Race Worksheet” by Julie Olson, Mitchell High School, Mitchell SD and “Gene to Protein - Transcription and Translation” by Drs. Ingrid Waldron & Jennifer Doherty, University of Pennsylvania 2 ATTENTION: When you separate the mRNA from the DNA, and when you move the mRNA to the ribosome, you will need to use your arrow keys on your keyboard, and not your mouse and touchpad! 14. Review: Watch this video on how a gene used to make a protein: From DNA to Protein (from 0:00 to 1:39). Part 2: TRANSLATION How are the right amino acids added in the right sequence to match the sequence of codons in the mRNA? Translation is more complicated than transcription; the shape and chemical structure of each amino acid does not match the shape and chemical structure of the corresponding mRNA codon. Instead, a special type of RNA, transfer RNA (tRNA), is required to ensure that the correct amino acid is brought in to match each codon in the mRNA. Look at the mini-codon chart in the upper right corner. This chart provides a key used by tRNA to translate from the mRNA “nucleotide language” to the amino acid “protein language”. 15. How many nucleotides make up a codon (section of mRNA): _________ 16. The “start” codon is ____ - ____ - ____ (3 letters) 17. A protein is a chain of ____________________. This chain is also called a ____________________. In the table below is the mRNA sequence. Write the matching tRNA “anticodons”, then play the game. mRNA AUG UCA AUG UCA AAA GAC CGA AAA GAC CGA UCA AUG AAA UGA Amino Acid 18. What was your time required for translation? Provide a screenshot for evidence. Insert the screenshot of your translation time here. 19. What happens to the tRNA after it brings the amino acids to the ribosome? When _____, then... As _____, meanwhile _____, finally... Following _____, _____, then_____… To check your understanding, complete the embedded quiz inside the simulator. 20. What was your score on the embedded quizzes? What was your time score in seconds? Provide a screenshot for evidence. Insert the screenshot of your number correct / incorrect and time score in seconds here. Open the Google Drawing below. Move the text boxes to fill in the blanks to label each type of molecule in the figure. Draw a rectangle around the third codon in the mRNA. Adapted from original materials: “Protein Synthesis Race Worksheet” by Julie Olson, Mitchell High School, Mitchell SD and “Gene to Protein - Transcription and Translation” by Drs. Ingrid Waldron & Jennifer Doherty, University of Pennsylvania 3 base pair cytoplasm codon ribosome cell nucleus polypeptide chain (protein) messenger RNA amino acids transfer DNA codon Review: Watch this video on how a gene is used to make a protein: From DNA to Protein. Now, try the whole process yourself in another activity: Transcribing and Translating. Tying It All Together Describe the steps necessary to turn a gene into a protein using the word bank and sentence frames below. Word Bank: transcription nucleus amino acid U-uracil folds mRNA translation ribosome genes tRNA First, _____, then _____, last _____. Initially, _____, meanwhile _____, finally_____. Prior to, _____, followed by _____, eventually _____. Adapted from original materials: “Protein Synthesis Race Worksheet” by Julie Olson, Mitchell High School, Mitchell SD and “Gene to Protein - Transcription and Translation” by Drs. Ingrid Waldron & Jennifer Doherty, University of Pennsylvania 4
