Unit 4 day 1 Flashcards
What is DNA considered?
It is considered a blueprint
What did Friedrich Miescher discover?
He discovered nucleic acids.
What is transformation?
It is the transfer of information.
Information determining virulence could pass from killed what strains into live strains?
Streptococcus
What does virulence mean?
It means harshness/severe.
The transforming material is most likely what?
DNA
The removal of protein did not destroy the ability of killed strains to transform live strains but removal of what did destroy the transforming ability?
DNA
What are bacteriophages?
viruses that infect bacteria
What are bacteriophages composed of?
only DNA and protein.
Bacteriophage DNA was labeled with what?
Radioactive phosphorus.
What is the short hand version of Radioactive phosphorus?
32P
Bacteriophage protein was labeled with what?
Radioactive sulfur
What is the shorthand for radioactive sulfur?
35S
DNA is what?
Genetic material
What does a nucleotide consist of?
A nitrogenous base at the 1’ carbon, a phosphate group at the 5’ carbon and a hydroxyl group at the 3’ carbon.
Nucleotides are polymerized to form what?
Nucleic acids
What is a phosphodiester bond formed between?
The 5’ phosphate of one nucleotide and the 3’ hydroxyl of the next nucleotide.
Each chain of nucleotides has a what to what orientation?
5’ to 3’
What does the Chargaff’s rules state?
Amount of adenine= amount of thymine. Amount of cytosine= amount of guanine
What are some components of the DNA structure that was discovered?
It is helical, the diameter is 2nm, and it makes a complete turn every 3.4 nm.
It was also proposed that DNA is a what structure?
Double helix.
What does the double helix consist of?
2 sugar-phosphate backbones.
Bases toward the interior of one strand form H bonds with what on the opposite strand?
Complementary bases.
The two strands are what?
Antiparallel.
For DNA replication what are three possible mechanisms?
Conservative, semiconservative, and dispersive.
Which of the 3 possible mechanisms proved to be correct?
Semi conservativism.
What is initiation?
It is the replication that begins at an origin.
What is elongation?
It is new strands of DNA that are synthesized by the enzyme DNA polymerase.
What is Termination?
It is replication that is terminated differently in prokaryotes ( circular chromosomes) and eukaryotes (linear chromosomes)
DNA polymerases bind to an origin and replication proceeds in what around the chromosomes?
In both directions.
What is a double helix unzipped by?
The enzyme helicase.
What is primase?
It is an enzyme that adds a short RNA primer sequence.
What is DNA polymerase III (pol III)?
It is an enzyme that adds nucleotides one at a time to the 3’ end of the new daughter strand of DNA.
DNA replication is what?
Semi discontinuous
Pol III Can only add nucleotides to the what end of the new strand?
3’
The what is synthesized continuously?
The leading strand.
The what is synthesized discontinuously?
The lagging strand
Replication moves in what synthesizing both strands simultaneously?
One direction
