DNA Replication

Question 1

semi-conservative replication

Answer 1

two parental strands separate, each one acting as a template for the new daughter strand

Question 2

conservative replication

Answer 2

the parental strands remains intact and th daughter strands are made of entirely new polynucleotides

Question 3

DNA polymerase III

Answer 3

begins DNA replication by recognizing and binding to an origin of replication sequence
forms phosphodiester bonds, powered by the hydrolysis of terminal dNTP phosphates
synthesisze new strand (5’ to 3’)
-REQUIRES DNA template and 3’-OH
-adds new deoxynucleoside triphosphates onto a growing DNA strand (dNTPs where N=A,T,C or G)

Question 4

origin of replication (ori)

Answer 4

short stretch of DNA within a chromosome that has a specific sequence indicating the start point for DNA replication

• usually only one per bacterial chromosome
• hundreds per eukaryotic chromosome

Question 5

helicase

Answer 5

enzyme that unwinds the two parental DNA strands in preparation for replication

Question 6

primer

Answer 6

a short stretch of RNA that helps to start DNA replication. It is complementary to the DNA strand and provides a 3’-OH for DNA polymerase III to add on to

Question 7

primase

Answer 7

the enzyme that synthesizes a short stretch of complementary RNA (primer) so that there is a 3’-OH for DNA polymerase III to begin adding dNTPs to

Question 8

DNA polymerase I

Answer 8

cuts out the RNA primers from the 5’ end of an okazaki fragment and incorporates new DNA onto the 3’ end of the adjacent fragment to fill in the sequence

Question 9

ligase

Answer 9

forms the phosphodiester bond between the 5’-P of one fragment and the 3’-OH in the adjacent