Study Questions: DNA structure and replication
 
1 DNA Structure
 
1. What is the relevance of understanding the mechanisms of genetic information maintenance and
                                                         retrieval for the field of pharmacy?
 
2. List the similarities and differences between the three main types of DNA double helix.
 
3. List three 3 forces that stabilize DNA double helix.
 
3. What are the hydrogen bonding features of a major groove sequence AT-GC-CG?
 
4. Why is negatively supercoiled DNA preferred for DNA replication?
 
5. Which of the following sequences is likely to be a R. E. site and why?
            G T A T A G
            G T T A A C
            A G G C C T
            T A A G C C
 
6. Draw the mechanism of DNA Ligase.
 
7. What are the cellular roles of DNA gyrase?
 
8. Why is ATP not required for Topoisomerase I activity?
 
9. Explain the mechanism of action of the drugs that target Topoisomerase I.
 
10. List two 2 drugs that target DNA gyrase. What is the mechanism of their action?
 
 
2. DNA Synthesis
 
1.   Draw the reaction catalyzed by DNA polymerase and explain its chemical mechanism.
 
2. What are the requirements for DNA polymerization?
 
3. Describe the proofreading mechanisms employed by DNA polymerase.
 
4. Describe the major features of DNA Pol I structure. What are their roles in DNA replication?
 
5. Draw the replication fork and describe the role of each protein involved in DNA replication.
 
6. Describe two types of mutations that can occur due to nucleotide mis-incorporation.
 
7. Describe how chemical DNA damage can lead to mutations.
 
8. How do mismatch repair proteins recognize the newly synthesized DNA strand?
 
9. List at least two 2 mechanisms of inhibiting DNA syntheses in tumor cells.