DNA replication Flashcards
What is the method of DNA replication known as and why
Semi conservative replication because half of the original DNA molecule is (conserved) kept in each of the two new DNA molecules
First step of DNA replication
- The originals DNA molecule is unwounded by the enzyme DNA helicase
Second step of DNA replication
- Hydrogen bond between the bases are broken by the unwinding and this forms two single polynucleotide DNA strands
Third step of DNA replication
- Each single polynucleotide acts as a template of the formation of a new strand
Forth step of DNA replication
- Free nucleotides are attracted to the exposed DNA bases by complimentary base pairing
Fifth step of DNA replication
- The new nucleotides are joined together by the enzyme DNA polymerase which catalyses condensation reactions to form two new paired strands
Sixth step
- The originals strand and the new strand joined together through hydrogen bonding
Two features of DNA structure which make DNA replication easier
Weak hydrogen bonds between bases which can be broken easily
Double stranded can be used as template / Complimentary base pairing used for template of new strand
What direction does the DNA polymerase go from
5’ to 3’
Further information about leading and lagging
Look in book because diagram heavy explanation (Remember though DNA pairs have opposite 5’ and 3’ directions )