This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate student’s writing of lab reports by providing this information in an editable file which can be sent to an instructor.
Exercise 1: Modeling DNA
The students must attach the DNA model to this lab report.
Note which nucleotides form pairs—cytosine and guanine, and adenine and thymine form pairs.
A. The following list indicates the bases on one strand of a DNA molecule. Write in the names of the bases that could pair with each to make the complementary strand.
cytosine| guanine| adenine| thymine|
adenine| Thymine| guanine| cytosine|
cytosine| guanine| thymine| adenine|
cytosine| guanine| guanine| cytosine|
B. What are the three components of a DNA nucleotide? How do these molecules connect together? - The three components of a DNA nucleotide are sugar deoxyribose, nitrogen containing bases, and phosphate groups. The molecules are all connected by covalent bonds.
C. What are the four bases found in DNA? Which of these bases pair together?
- The four bases found in DNA are Adenine, guanine, thymine, and cytosine. Adenine pairs with thymine and cytosine pairs with guanine.
Exercise 2: The Globin Gene
1. Complete the DNA molecule by writing a complementary strand.
Coding Strand:CGT CTC TTC GGA CAC Complementary Strand: GCA GAG AAG CCT GTG 2. Write the mRNA sequence that will be created in the process of transcription. The DNA coding strand has the information for the gene, so the strand must be transcribed. The relationships are slightly different for RNA, because RNA does not have T; therefore, U should be substituted for T. To transcribe DNA to RNA, the pairing relationship is A – U, T – A, C – G, and G – C, respectively.
Coding Strand:CGT CTC TTC GGA CAC
mRNA Strand: GCA GAG AAG CCU GUG
3. Translate the mRNA into amino acids. Use Table 1 as a reference. Remember, when a “stop” codon is recognized, the protein creation is terminated.
Amino Acids Formed: Phenylalanine Leucine Isoleucine Valine
A. How many nucleotides would it take to construct the mRNA coding strand of the β-subunit of the hemoglobin A molecule? - I think it would take about 441 nucleotides to construct the mrna coding strand of the b subunit of the hemoglobin A molecule.
B. How many nucleotides would it take to model the entire β-subunit of the hemoglobin A molecule?
- It would take 438 nucleotides to model the entire b subunit of the hemoglobin A molecule.
C. Is the β-subunit of the hemoglobin A molecule a complete DNA molecule (chromosome) or part of one? Explain.
- I don’t think that the b-subunit of hemoglobin A molecule is a complete DNA molecule or part of one because it only has contains 4 subunits and most genes contain thousands of bases.
D. What would happen if one of the DNA nucleotides was deleted? What if the first T was substituted for an A? Would a substitution always result in a change? Explain why or why not.
- I think it would change because the way they are paired up makes a difference in the result and if you change one I do believe it will have a different result.
E. Using your newly formed model of DNA from Exercise 1, write the coding strand below. Use the coding strand to determine the mRNA strand and the amino acids formed. Do this separately for Row 1 and Row 2 of your DNA model.
Data Table: Newly Formed Model of DNA from Exercise 1|
| ROW 1| ROW 2|