lecture 2

Question 1

22. Regarding DNA replication, DNA replication begins at the ______________ site and ends at a specific site called the _______________. Fill in the blanks.

Answer 1

origin, terminus

Question 2

23. Regarding DNA replication, What is the main function of something within the polymerase class of enzymes?

Answer 2

Enzyme that is responsible for placing nucleotides

Question 3

24. Regarding DNA replication, which statement accurately describes the function of (a) DNA polymerase I, (b) DNA polymerase II, or (c) DNA polymerase III?

Answer 3

-Adds new nucleotides to the end, the starting point
-a short stretch of DNA or RNA nucleotides hydrogen bonded to its complete strand. Responsible for all repairs
-main synthesizing, synthesizing all the nucleotides like a train, and most responsible for the bulk of DNA synthesis.

Question 4

25. Regarding DNA replication, what is a primer?

Answer 4

Starting point

Question 5

26. Regarding DNA replication, what happens if no primer is present?

Answer 5

You cannot continue with the process, with no starting point, nothing can’t happen

Question 6

27. Regarding DNA replication, what is the main function of an nuclease?

Answer 6

Things that remove any nucleotides that do not belong there and must be cut out

Question 7

28. Regarding DNA replication, what is the difference between an endonuclease and an exonuclease?

Answer 7

Endonuclease- inside Exonuclease- outside

Question 8

29. Regarding DNA replication, which statement accurately describes a (a) difference or (b) similarity between the leading and lagging strands of DNA templates?

Answer 8

Leading is continuous, lagging is discontinuous, and has to be made with fragments

Question 9

30. The site of the opening of the DNA strand where active replication occurs (and other enzymatic activities) is called the ______________. Fill in the blank.

Answer 9

Replication Fork

Question 10

31. Regarding DNA replication, which statement accurately describes the function of (a) helicase, (b) primase, (c) DNA gyrase, or (d) DNA ligase?

Answer 10

1. Helicase - the area that is going to unwind the DNA double helix and open up the replication fork.
2. Primase - makes primers
3. DNA gyrase - Relieves torque, and doesn’t allow the DNA to get all bound up. Zips up the DNA behind the replication fork. Prevents DNA from tangling up. Allows no breakage or twisting.
4. DNA ligase - located at the end of DNA. Joins the ends of DNA segments + Does DNA repair

Question 11

32. Regarding DNA replication, what is the definition or function (i.e. why is it needed) of a single-stranded binding protein?

Answer 11

Stabilizes single-stranded regions which are usually not stable in Aqueous environments.

Question 12

33. There are three main stages of DNA replication. Which statement describes the initiation stage (only as discussed in class)?

Answer 12

Initiation - initiating the process and getting all of the stuff ready, recognition of specific sites, other protein formation, opening of the replication fork

Question 13

34. There are three main stages of DNA replication. Which statement describes the elongation stage (only as discussed in class)?

Answer 13

Elongation - DNA polymerase III (is going to create all new nucleotides) add successive nucleotides to the strands

Question 14

35. There are three main stages of DNA replication. Which statement describes the termination stage (only as discussed in class)?

Answer 14

Termination - Finishing point, DNA gyrase, a termination site

Question 15

36. What is the difference between eukaryotic and prokaryotic DNA replication (know the chart on PPT Chapter 14 Slide 21)?

Answer 15

THE CHART IS ON THE DOC

Question 16

37. What is a similarity between eukaryotic and prokaryotic DNA replication (know the chart on PPT Chapter 14 Slide 21)?

Answer 16

-Pre-existing DNA,
-The direction of replication both 3-5 and 5-3,
-Replication model semi conservative