DNA replication

Question 1

Describe process of DNA replication

Answer 1

It is semiconservative, semi discontinuous and bidirectional

Question 2

Consequences of DNA replication

Answer 2

Beginning of process commits to this division
Division-not take place before completion
Must not be interrupted otherwise progeny will not form

Question 3

Origin

Answer 3

2 points where origin takes place, two strands that separate

Question 4

Replicon

Answer 4

part of genome where replication takes place, contains origin of replicate

Question 5

Replication fork

Answer 5

Area where two strands separate and DNA synthesis takes place

Question 6

Replication in E.coli

Answer 6

Origin: oriC
minimum DNA sequence
TerC1 and TerC2 signals where replication must start
Tus gene binds to these proteins and terminates process

Question 7

What happens after termination?

Answer 7

DNA dimer has site specific recombination with the aid of XerC and XerD recombinases

Question 8

Why does E.coli have an increased replication rate?

Answer 8

E,coli divides faster once every 60 minutes as replication takes place before cell division
Bacteria does this anomaly by growing bacteria at multiple replication forks
Start of cell division-cell mass / volume
Mass of individual cells grow higher

Question 9

How does E.coli ensure only one genome per cell during exponential growth?

Answer 9

Bacterial genome bound to cell membrane this interaction requires DNA sequence-460bp including oriC
Genomic DNA undergoes methylation on adenine in sequences after Dam methylation has taken place partially, after semiconservative replication does oriC bind to cell membrane.
OriC binds once to cell membrane during replication-association is responsible for segregation of two genes