DNA

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Headshot of Ted Chauvin, PhD · Associate Professor
Ted Chauvin
PhD · Associate Professor
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This chapter, Chapter 30: DNA Structure, Replication, and Repair, is an excellent chapter on DNA. I’ve also attached the pdf below of the chapter.

Chapter 30: DNA Structure, Replication, and Repair. In: Abali EE, Cline SD, Franklin DS, Viselli SM. Lippincott Illustrated Reviews: Biochemistry. 8th ed., international ed. Philadelphia; Baltimore; New York: Wolters Kluwer; 2022.

As usual, below is the need to know list for DNA. There is a lot here, and all of it is high-yield information.

Diagram and describe the molecular and chromosomal structure of DNA and explain how this organization supports replication, gene expression, and cell division

  • DNA 

  • DNA structure 

  • Chromatin 

  • Chromosome 

  • Histones 

  • Nucleosome 

  • Heterochromatin 

  • Euchromatin 

 

Diagram and describe the process of DNA replication and explain how therapeutic agents target key enzymes involved in this process 

  • Origin of replication 

  • Replication fork 

  • Single-stranded binding proteins 

  • Helicase  

  • Topoisomerase I and II 

  • Primase  

  • DNA pol III 

  • DNA Pol I 

  • DNA ligase 

  • Telomerase 

  • Dyskeratosis congenita 

  • Acyclovir 

  • Etoposide 

 

Diagram and describe DNA repair mechanisms and explain their relevance to disease prevention and therapeutic strategies 

  • Types of DNA Damage 

  • Base excision repair 

  • Nucleotide excision repair 

  • Mismatch Repair 

  • Homologous recombination 

  • Non-homologous recombination 

  • Lynch syndrome/HNPCC 

  • Xeroderma pigmentosum 

  • Ataxia telangiectasia  

  • Fanconi anemia  

 

Diagram and describe the molecular and chromosomal structure of DNA and explain how this organization supports replication, gene expression, and cell division

Osmosis video on DNA structure.

Osmosis video on Nuclear Structure. This video focuses on chromosomal structure.

Diagram and describe the process of DNA replication and explain how therapeutic agents target key enzymes involved in this process

Osmosis video on DNA replication.

Pharmaceuticals that target DNA replication

Below are examples of some pharmaceuticals that target DNA replication. These are examples; there are many more available. 

A synthetic acyclic guanosine analog with potent activity against herpes simplex viruses type 1 and 2 (HSV-1, HSV-2). Acyclovir inhibits viral DNA synthesis. Acyclovir is converted to the monophosphate form by viral thymidine kinase (TK), diphosphate by cellular guanylate kinase, and triphosphate by various cellular enzymes. Acyclovir triphosphate stops the replication of herpes viral DNA by the following three mechanisms: competitive inhibition of viral DNA polymerase, incorporation into and termination of the growing viral DNA chain, and inactivation of the viral DNA polymerase.

(Adapted from Zovirax (acyclovir capsule, tablet, suspension) package insert. Newtown, PA: Prestium Pharma, Inc.; Oct 2014.)

A direct inhibitor of DNA synthesis. It works by binding to the enzyme-DNA complex to stabilize DNA strand breaks created by DNA gyrase and topoisomerase. Ternary complexes of drug, enzyme, and DNA block the progress of the replication fork. 

Interacts with topoisomerase II within a cell if a cell is exposed to etoposide, a stabilization of the enzyme-DNA complex results in double- and single-strand breaks in DNA and cell-cycle arrest.

Diagram and describe DNA repair mechanisms and explain their relevance to disease prevention and therapeutic strategies

Osmosis video on DNA damage and repair.