Lecture 8 Flashcards
What experiment confirmed DNA as the genetic material?
Prokaryotic bacterium transformation- Frederick Griffith
Explain Frederick Griffiths experiment and why one died and one didn’t
injected two strains of a bacteria into lab mice. The S strain killed the mouse because it has a polysaccharide coat that protects the bacteria from the hosts defence system. The mouse with the R strain survived because the R strain lacks the coat and is able to be destroyed by the host defence. The pathogen was recognized
what was the point of Hershey-chase experiment?
to determine whether genes were made of protein or DNA
what is a nucleotide structure (DNA and RNA)
phosphate, sugar, a nitrogenous base (ATGCU)
which way is a DNA sequence read from
5’ end to the 3’ end
How is a DNA structure composed (2)
- two strands, running antiparralel (double helix)
- Nitrogenous bases are connected by H bonds
where does DNA replication happen
Nucleus
what does helicase do
unwind the DNA strand
primer in primase is made of what
RNA
what do single stranded binding proteins do
bind to the DNA strands to keep them separated after helicase
What does Topoisomerase do ?
keeps the DNA from super coiling which needs to be controlled during DNA replication
which direction does DNA polymerase build in
5’ to 3’ (but starts at 3’ on original strands)
why is it called a lagging strand
the primase has to keep putting primer to tell the DNA polymerase where to build and it results in Okazaki fragments
what does ligase do
sticks the Okazaki fragments back together
what are DNA and RNA
Nucleic acid
