biolofy

DNA and Protein Synthesis
Hands-On Labs, Inc. Version 42-0051-00-01

Lab Report Assistant

Name______________________________________

Exercise 1: Modeling DNA

Questions

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

adenine

adenine

guanine

cytosine

thymine

cytosine

guanine

B. What are the three components of a DNA nucleotide? How do these molecules connect together?

C. What are the four bases found in DNA? Which of these bases pair together?

Exercise 2: The Globin Gene
Procedure

1. Complete the DNA molecule by writing a complementary strand.

Coding Strand: CGT CTC TTC GGA CAC Complementary Strand:
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:

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.

mRNA Strand:

Amino Acids Formed:

Questions

A. How many nucleotides would it take to construct the mRNA coding strand of the β-subunit of the hemoglobin A molecule (refer to the bottom of p.146)?

B. Is the β-subunit of the hemoglobin A molecule a complete DNA molecule (chromosome) or part of one? Explain.

D. What would happen if one of the DNA nucleotides was deleted? What if the