Chapter 14: DNA Structure and Function

  1. What is the fundamental unit of DNA?
  2. What are the components of a deoxyribonucleotide?
  3. Draw a deoxyribonucleotide.
  4. Which end of the deoxyribonucleotide is the 5’ end? The 3’ end?
  5. Name four nitrogenous bases.
  6. What are the bonds between nucleotides are called?
  7. Which direction is DNA read?
  8. Watson and Crick proposed three hypotheses regarding the secondary structure of DNA. What were they?
  9. Define antiparallel.
  10. Base pairing is complementary. What does that mean?
  11. What is the backbone of DNA made of?
  12. Who was Rosalind Franklin?
  13. Be able to explain the different alternate hypotheses for DNA replication: semiconservative, conservative, and dispersive replication. How are they different?
  14. What did the Meselson-Stahl experiment seek to determine.
  15. What was the experimental design of the Meselson-Stahl experiment.
  16. What is Nitrogen-15 (15N)? What is Nitrogen-14 (14N)? Which one is more common?
  17. In the Meselson-Stahl experiment, what was low-density DNA? Intermediate-density DNA? High-density DNA?
  18. What were the prediction for the ratio of low density DNA: intermediate density DNA: high density DNA for each of the alternate hypotheses for replication (semiconservative, conservative, dispersive)?
  19. What were the results of the Meselson-Stahl experiment? How did they support the semiconservative hypothesis?
  20. What does DNA polymerase do?
  21. What is a replication bubble?
  22. Replication of DNA happens bidirectionally. What does that mean?
  23. How does the origin of replication differ between bacteria and eukaryotes?
  24. What are the steps of the synthesis of the leading strand of DNA?
  25. What function does helicase serve?
  26. What function do the single-strand DNA-binding proteins serve?
  27. What is the helix stabilized by?
  28. The unwinding of the helix creates _________ .
  29. What does topoisomerase do?
  30. What is the function of primase?
  31. What is the function of the replisome? How many replisomes are there per replication bubble?
  32. What is the leading strand during replication? The lagging strand? Which one is more efficient?
  33. What are the five steps of the synthesis of the lagging strand?
  34. What is an Okazaki fragment?
  35. What is the function of DNA ligase?
  36. What are telomeres?
  37. How is the telomere of the leading strand copied?
  38. How is the telomere of the lagging strand copied?
  39. Why is replicating the end of the telomere a problem for the lagging strand?
  40. When the primer is removed from the telomere of the lagging strand, what happens?
  41. Telomere don’t contain genes? What are they made of?
  42. What is the function of telomerase?
  43. How accurate is the synthesis of DNA?
  44. How does DNA edit mistakes it makes during synthesis?
  45. What are repair enzymes?
  46. What does DNA polymerase III do?