DNA & Protein Synthesis Exercise…
DNA Protein Synthesis exer Lab Report Name: ________________________ Section: ______________________ DNA & Protein Synthesis Exercise 1 – Modeling DNA Observations from Procedures: 1. What are the three components of a DNA molecule nucleotide? 2. What is the sugar found in DNA molecules? 3. List the four bases which are unique to DNA. 4. Fit any six nucleotides together to form a row, then list the six nucleotides in the order you used them. (Hint: The PO4 will be connected to the sugar, where as the nucleotide will bonded to the sugar. D-P-D-P-D-P This creates the “backbone” of the DNA molecule allowing the nucleotide bases to interact with each other.) 5. Work with your model pieces and try fitting the bases together to make a double strand as shown in the illustration above. Write in the names of the bases that could pair with each to make the complimentary pairs. cytosine _______________ thymine _______________ adenine _______________ guanine _______________ 6. After determining the pairing pattern of the nitrogenous bases, add the missing bases to this hypothetical strand of DNA. (A=adenine, C=cytosine, G=guanine, T=thymine) 3’ 5’ A C G G T C T A C C 5’ T G 3’ 1 Exercise 2 - The Globin Gene Observations from Procedures: 1. Use the DNA coding strand below to complete the DNA molecule by creating a complimentary strand. To do this, remember that the nucleotide base pair association between DNA is A -T and G –C. Write the DNA complimentary strand for this portion of the hemoglobin ?-subunit. Coding Strand: CGT CTC TTC GGA CAC Complimentary Strand: _______ ______ ______ _______ _______ 2. Write the mRNA sequence that will be created in the process of transcription. Remember that the coding strand of the DNA is the strand that has the information for the gene, so you must transcribe the coding strand. To go through the process of transcription the DNA – RNA pairing relationship is A - U, T – A, C - G and G – C. Coding Strand: CGT CTC TTC GGA CAC mRNA Strand: _______ ______ ______ _______ _______ codon #1 codon #2 codon #3 codon #4 codon #5 3. Translate the mRNA into amino acids. Use Table 1 for the correct amino acids or this link: http://hyperphysics.phy-astr.gsu.edu/hbase/Organic/gencode.html Write your amino acid sequence starting with codon #1. First amino acid + Second amino acid + Third amino acid + Fourth amino acid + _____________ _ + _______________ _ + ______________ _ + _______________ _ + Questions: 4. What would happen if one of the DNA nucleotides was deleted? 5. What if the first T was substituted for an A? 6. Would a substitution always result in a change why or why not? Lab Report Name: ________________________ Section: ______________________ 7. How many nucleotides would it take to construct the coding strand of the entire 146 amino acid globin molecule? 8. How many nucleotides would it take to model this part of the double stranded DNA molecule? 9. Do you think this is a complete DNA molecule (chromosome) or part of one? Explain. 10. What molecule of all that you have worked with in this exercise has ultimate control over protein synthesis? Explain you answer. 3