How Does DNA Direct Protein Synthesis



Name: ________________________________________________Block: ______ Date: _________How Does DNA Direct Protein Synthesis Lab?IntroductionProtein synthesis is a complex process. In this activity you will trace the steps that are involved in protein synthesis. KeywordsDNA mRNA tRNArRNAtranscription translation amino acidprotein synthesisProcedure1. DNA cannot leave the nucleus with the genetic code so it serves as a template for mRNA (messenger RNA) to copy the code and transfer it to the ribosome, which is called transcription. Write the sequence of mRNA codons that would result from the transcription of this portion of DNA. DNA:TAC ATA TAG CTT TTG ACG GGG AAC CCC ATTmRNA: ____ ____ ____ ____ ____ ____ ____ ____ ____ ____2. After transcription mRNA attaches to a ribosome and is joined by the corresponding tRNA (transfer RNA), which carries a single amino acid based on the anticodon. Recall from biochemistry amino acids are the building blocks of proteins. As tRNA carries the amino acids to the ribosome the proteins are synthesized based on the code sequence carried on the mRNA. This process is called translation. The tables show the mRNA codons and the amino acids for which they code. For example, if you were given the mRNA codon AGA, you can see on the table that these bases code for the amino acid Arginine. Use the mRNA sequence above to write the sequence of amino acids carried by the tRNA.Amino Acids: __________, __________ , __________ , __________ , __________, __________, __________ , __________ , __________ , __________.Questions1. How many amino acids make up the portion of the newly synthesized protein from the above question? ____________2. What is the purpose of the UAA codon?3. What do the letters RNA stand for? __________________________________________________________________4. How is mRNA different from DNA? ____________________________________________________________________________________________________________________________________________________________________5. On mRNA, what nitrogen base binds with the DNA base:A?______ G?_____ T?______ C? ______6. Where in the cell is mRNA made? ___________________________________________________________________7. What enzymes are used in the process of transcription? __________________________________________________8. What carries the amino acids to the ribosome where it joins with the mRNA? __________________________________9. How are mRNA and tRNA alike? _____________________________________________________________________________________________________________________________________________________________________10. How are mRNA and tRNA different? _________________________________________________________________________________________________________________________________________________________________11. What determines what proteins are made? ___________________________________________________________Label the diagram:A. _________________B. _________________C. _________________D. _________________E. _________________F. _________________G. _________________Online Animation:Log on and click on the RNA Protein Synthesis Links and explore transcription and translation. Web Page 1: Read, think about the diagrams and study the process. Page 2: Practice the process of protein synthesis. Be sure to read the bold text below the diagram for instructions on what to do! It does not take long so you might want to try a couple of times to be sure you know how to transcribe and translate the DNA sequence into a protein. ................
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