Question

2) (2 pts) The diagram below depicts two Okazaki fragments synthesized during lagging strand DNA replication. Which arrow indicates the position at which the synthesis of the next RNA primer will be initiated? Circle the correct letter 3 5 Template strand 3) (2 pts) The E. coli genome encodes 3 different DNA polymerases, namely, L,II and II. a) Which one has 5' to 3' exonuclease activity? Why? b) Which one is most abundant?

Answer 1

2.C-the position for next RNA primer synthesis.

Synthesis of okazaki fagments begins with RNA primer-On the lagging strand the sythesis of Okazaki fragment requires a new initiation event. Thus short pieces of RNA are made at replicaiton fork. These primers are complementary with lagging strand.

3a) DNA polymerase I has 5'-3' exonuclase activity. During replication RnaseH removed the RNA primer from lagging strand and polymerase I fills the empty place in between the okazaki fragments at 5'-3' direction for proofreading.

b) DNA polymease I. Its responsiblle for more 95%polymerase activity