Question

 a) Annotate this figure to show the proper location of each of the following:

 • template DNA strand polarity

 • DNA polymerase

 • Topoisomerase (gyrase)

 • leading strand daughter fragment(s)

 • lagging strand daughter fragment(s)

 •Single stranded binding proteins

 • DNA polymerase II

 • Primase

 • Ligase

 •Helicase

Answer 1

· Two strands of DNA are oriented in opposite direction or complementary, one being 3’to 5’, other in 5’to 3’direction.

· Mode of replication is considered as semi-conservative.

· Each DNA strand act as template to synthesize new complementary DNA strand.

· Semi-conservative replication results in synthesis of two DNA molecules, in which one old strand is retained and one new strand is generated.

· Both prokaryotic and eukaryotic organisms have DNA polymerase enzymes that help in DNA polymerization during replication.

· DNA polymerase has 5’ to 3’ polymerization activity.

· Thus, leading strand is synthesized continuously.

· Lagging strand is synthesized in discontinuous manner as Okazaki fragments, which are later ligated.

s' leading strand SSB DNA POLYMERAS EM GYRASE pero CASE ANA POLYMERASE) LIGASE PRIMASE Laggistrand (single stranded bidding proteins) I strand