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Flashcards in DNA Replication Deck (17):
1

Semi-conservative replication

Each of the 2 Daughter DNA molecule has 1 old strand derived from the parent DNA molecule and 1 newly synthesised strand

2

Origins of replication

Replication of DNA molecule begins at specific sites called origins of replication

3

Replication bubble
Replication fork

The two polynucleotide strands separate and form a replication bubble. At each end of a replication bubble is a replication fork

4

Both directions

Replication of DNA proceeds in both directions

5

Topoisomerase

Topoisomerase creates a transient break by kicking a strand of DNA. This helps to unwind the double helix (prevent supercoiling) ahead of the replication fork

6

Helicase

Helicase catalyses the breakage of hydrogen bonds between complementary base pairs, thus separating the two parental DNA strands

7

Single stranded binding proteins

SSB proteins bind tightly to single stranded regions of DNA to help maintain the stability of the replication fork

8

Primase

An enzyme called primase catalyses the synthesis of RNA primer in 5' to 3' direction

9

RNA primer

RNA primer is to initiate DNA polymerisation

10

DNA polymerase (I)

DNA polymerase (I) later replaces RNA nucleotides of the primers with DNA nucleotides

11

Deoxyribonucleoside triphosphates (dNTPs)

deoxyribonucleoside triphosphates (dNTPs) align along the template strands by complementary base pairing i.e. Adenine to thymine, Guanine to cytosine

12

DNA polymerase (III)

DNA polymerase (III) catalyses the formation of a phosphoester bond between the 3' hydroxyl group of the last nucleotide in the growing strand and the 5' phosphate group of the incoming dNTP

13

Anti parallel

Each growing new DNA strand is antiparallel to its parental template strand

14

Leading strand

The leading strand is synthesised continuously as a single polymer along the template strand

15

Lagging strand
Okazaki fragments

Lagging strand is synthesised discontinuously as a series of short fragments called Okazaki fragments along the template strand

16

DNA ligase

DNA ligase catalyses the formation of a phosphoester bond between the 3' end of each new Okazaki fragment and the 5' end of the growing strand to form a continuous strand

17

Daughter DNA molecule

Each Daughter DNA molecule consists of a newly synthesised strand and a parental strand