DNA. replication Flashcards
Step 1
The enzyme DNA helicase. breaks down he. hydrogen bonds. between the nitrogenous base and unwinds the DNA
Step 2
The free nucleotides. are attracted to the. exposed complementary bases
Step 3
The enzyme DNA polymerase initiates a condensation reaction once the bases have paired up. This reaction forms phos-digester. bonds to connect the sugar-phosphate backbone
Semi-conservative replication
Each new DNA molecule has one original polynucleotide and one new polynucleotide. In effect each original strand. acts as a complementary template for the new strand.
Meselson and Stahl experiment
Bacteria was cultured with 15N until all. the DNA was heavy. Then it was transferred to a place with only 14N and was allowed to reproduce
What happened in the Meselson and Stahl experiment
when the heavy DNA was replicated with light DNA in the first time round 2 different Hybrid strands were formed, however on the second replication with light DNA both two different light DNAs were formed, as well as two more different hybrid DNAs were formed. This shows that each polynucleotide is used as a template during replicated, proving that the Semi-conservative theory is true.