Molecular Genetics - DNA Synthesis Flashcards
DNA replication happens in this fashion.
Semi-Conservative
- Each strand is a template
- Remains unaltered
The steps in the semi-conservative fashion?
Unwind
Seperate
Each strand is a ‘template’
IN DNA replication we start with one ___ to these____ to these.
Mother strand -> 2 strands (One strand from mother, one identical)
2->4 Strands (Maternal/new strand, daughter/new strand)
T/F Without mutations there would be no evolution.
TRUE
The initiation of DNA replication starts at…
Specific points of origin, sequences recognized by enzymes.
In Bacteria there is ____ origin of replication.
One
Enzymes in the Initiation Phase?
HTSPD
Helicase Topoisomerase (Single-strand DNA binding proteins) Primase DNA Polymerase III
This enzyme unwinds & seperates the double helix. How?
Helicase - breaks hydrogen bonds
Which enzyme forms the replication fork?
Helicase!
The leading strand opens in the __-__ direction and is ________.
3-5, continuous
Lagging stand opens in the __-__ direction and is ____________.
5-3, discontinuous
This enzyme alleviates strain and periodically repairs cuts in strand (relieving pressure & tension)
Topoisomerase
This guy prevents re-annealing, but isn’t an ______.
Single-Strand DNA Binding Proteins
Isn’t an enzyme
This binds single stranded DNA & acts as the RNA primer.
Primase
Primase is responsible for making a ______ ________ _______ as ____-___.
Hybrid Double Helix as dsDNA-RNA
After primase works, the ds-NA is ready to be bound by
Polymerase
This enzyme begins the synthesis of new DNA.
Polymerase
The new DNA strand is synthesized in the __-__ direction.
5-3
This is called the leading strand because…
It can continuously synthesize
DNA Polymerase III kicks off the __ _____ _______ and only adds to the __’ end.
2 extra phosphates, and adds to the 3’ end.
Nucloside triphoshphates, are added to the
3 Prime end only (ATP, GTP, CTP, TTP)
The energy for the reaction to occur comes from:
Nucleotides
Once DNAP3 is involved, DNA _______ and is ______.
Elongates, Read
The lagging strand, on the other side, opens in the __-__ direction
3-5