DNA Replication/Transcription/Translation Lab Worksheet Understanding DNA Replication Directions: Using model materials to demonstrate DNA replication: (Drawn at the bottom of the page) 1. On a separate Word document, present a detailed analysis of DNA replication at one replication fork. Use drawing, descriptions, and/or captions detailing the process. 2. In the analysis include the following: a. Show how the leading and lagging strands are synthesized b. Show the proteins (enzymes) involved in DNA replication and what their functions are Understanding DNA Transcription and Translation Directions: Complete the following questions. Questions 1- 3 can be submitted on the same document as the Understanding DNA Replication assignment. Refer to Figure 1 as it illustrates the process of DNA transcription, translation, and protein synthesis. 1. The stages of transcription are initiation, elongation, and termination. Draw a representation of each of these stages in a separate Word document. Be sure to include the names of important enzymes and locations. 2. Once mRNA is created through transcription, it is often processed. Explain how mRNA can be processed. Include the names of important enzymes or structures. During transcription, the DNA of a gene serves as a template for complementary basepairing, and an enzyme called RNA polymerase II catalyzes the formation of a pre-mRNA molecule, which is then processed to form mature mRNA. 3. Translation is how mRNA gets used to create a peptide sequence. Draw what is going on inside a ribosome. Be sure to include the locations of mRNA, tRNA, each subunit of the ribosome, and where the amino acid sequence forms. . Figure 1. The Central Dogma of Molecular Genetics: DNA Codes for RNA, and RNA Codes for Protein. DNA Transcription and Translation Exercises (Converting DNA template Sequences and Identifying types of Mutation Name: Section: ID Number: Directions: Now that you have gone through the steps on how to convert you will be in charge of converting a DNA template sequence into an amino acid produce. In the figure below the template strand is labeled. The DNA template is what is used to create a representative mRNA strand. You can see its complementary DNA strand as well as the mRNA strand. Take care to note the direction of the strands (3’ends and 5’ ends). Once an mRNA strand is created then the mRNA can be used to code for an amino acid sequence. The table below shows how the mRNA strand was converted into a peptide. Table 1. mRNA Strand Converted into a Peptide DNA Template Strand 3' T A C T DNA 5' A T mRNA 5' A U G A Amino Acid Met T C A A A C C G A T T 5' G A A G T T T G G C A G U U U G G C Lys Phe Gly T A A 3' U A A 3' - Amino Acid Ser Val Asp Gin Ile 2. Mutations in DNA can affect the peptide product that is being coded. Below is a wild type gene along with a series of mutations of that same gene. Determine the type of mutation as well as how it affects the final peptide sequence. Wild type: DNA Template Strand 3' T A C T T C A A A C C G A T T 5 ' DNA 5' A T G A A G T T T G G C T mRNA 5' U A C U U C A A A C C G A U U 3' Amino Acid Tyr Mutation: Substitution DNA Template Strand Phe Lys Pro A A 3' Ile Effect: alter/change function 3' T A C T T C A A A C C A A T T 5 ' DNA 5' A T G A A G T T T G G T T A A 3' mRNA 5' U A C U U C A A A C C A A U U 3' Amino Acid Tyr Mutation: Substitution DNA Template Strand Phe Lys Pro Ile Effect: alter/change function 3' T A C T T C A A A T C G A T T 5 ' DNA 5' A T G A A G T T T A G C T A A 3' mRNA 5' U A C U U C A A A U C G A U U 3' Amino Acid Tyr Phe Lys Ser Ile Mutation: Deletion DNA Template Strand Effect: Alter function 3' T A C T T C A A C C G A T T 5' DNA 5' A T G A A G T T G G C T A A 3' mRNA 5' U A C U U C A A C C G A U U 3' Amino Acid Tyr Phe Mutation: substitution DNA Template Strand Pro Ile Effect: alter/change function 3' T A C A T C A A A C C G A T T 5 ' DNA 5' A T G T A G T T T G G C T A A 3' mRNA 5' U A C A U C A A A C C G A U U 3' Amino Acid Tyr Mutation: insertion DNA Template Strand Ile Lys Pro Ile Effect: may not function properly 3' T A C A T T C A A A C C G A T T 5' DNA 5' A T G T A A G T T T G G C T mRNA 5' U A C A U U C A A A C C G A U U 3' Amino Acid Tyr Ile Gin Thr A A 3' Asp 3. What mutations would have the greatest effect on peptide sequence? Which would have the least effect? Why? The nonsense mutation will have the greatest effect on peptide sequence because it creates a stop codon where the sequence should be continuing .