5 Written Questions
5 Matching Questions
- Discontinuous replication hypothesis
- Replication bubble
- Leading strand
- Dispersive replication
- DNA Polymerase
- a forms in chromosome that is actively being replicated. There are forks at the ends of the bubble.
- b Once a primase synthesizes an RNA primer on the lagging strand, DNA polymerase might synthesize short fragments of DNA along the lagging strand and these fragments would later be linked together to form a continuous whole. This was tested by Okazaki.
- c An enzyme that catalyzes the elongation of new DNA at a replication fork by the addition of nucleotides to the existing chain. It's exorgonic because monomers act as subtrates.
1 Chrosmosome being replicated
2 bacterial chromosomes have a sine orgin of replication
3 eukaryotic chromosmes have multiple origins of replication
- d parent molecules is cut into sections such as the daughter molecules contain old DNA interspected with newly synthesized DNA.
- e Enzyme's product. Its called this because it deads to replication fork and is syntheiszed continuously in the 5' to 3 ' direction.
5 Multiple Choice Questions
- Enzymes that add more repeating bases to the end of the lagging strand. (stem cells have telomerase. Most dont have this)
- removes RNA primer at the begining of each okazaki fragment and fills gaps. The enzyme DNA ligase then joins the Okazaki frapments to form a continuous DNA strand.
- Cuts and rejoints DNA downstream of the replication fork to relieve tension.
- Prevent from closing
- After watson and crick suggested that the existing strands of DNA served as a template biologists proposed 3 alternatives.
1 Semiconservate replication
2 conservative replication
3 dispersive replication
5 True/False Questions
Xeroderma Pigmentosum (XP) → rare autosmal recessive disease in humans characterized by the developemtn of skin lesions.
XP is caused by mutations of one of several nucleotide excision repair systems. These mutations mean that the cells of people with XP cannot repair DNA damaged by ultraviolet radiation.
Hershey-Chase Experiment → Studied whether genes were made of proteins or DNA. They studied how a T2 virus infects the bacterium e coli. T2 inject its genes into cell. These genes direct production of new virus particles. did this in the presence of 32P and 35S
Hypothesis: if genes consist of DNA then radiactive DNA found inside the cells while proteins outside of cells. RAdioactive DNA was found in the pellet.
Enzyme helicase → Enzyme that joins okazaki fragments to form a continous DNA strand
Conservative Replication → parental molecules serves as a template for sythesis of and entirely different molecule
Primase → Enzyme that joins okazaki fragments to form a continous DNA strand