2.7 DNA replication, transcription and translation Flashcards
What is semi-conservative replication?
Where one strand is new and the other stand is from the parent molecule.
What is conservative replication>
Both strands are new
What is dispersive replication?
Mixture of new and old in both stands.
Who published song evidence for semi conservative replication?
Meselson and Stahl they used different isomers of nitrogen.
What are the stages of DNA replication?
- helicase unwinds the double helix and separates the two strands.
- DNA polymerase links nucleotides together to form new strands
- daughter DNA each rewind into double helix
What is transcription?
the copying of the base sequence of a gene by making a RNA molecule.
What is translation?
The synthesis of polypeptides on ribosomes using mRNA and tRNA.
The transcription and translation of RNA and DNA?
- RNA polymerase moves along gene separating DNA into separate strands
- RNA nucleotides are assembled along one of the strands of DNA by complementary paring but instead of thymine with uracil.
- RNA nucleotides link together by covenant bonding between pentose sugar and phosphate
- RNA strand separates from DNA
- DNA strand pairs up again and twist back into double helix.
How is the amino acid sequence determined?
By mRNA
What is a codon made from?
a group of 3 bases.
What is a codon?
the genetic code that is translated on the ribosome
What does translation depend on?
The paring between codons on mRNA and tRNA.
Why is the genetic code degenerative?
because there is more than 1 codon for each amino acid.
Where does helicase split DNA?
The replication fork.
What is the starting codon?
AUG
