Methods 2

Question 1

how could we find the origin of gene/geome?

Answer 1

let replication begin at the ori, will proceed in both directions; denature to let okazaki fragments fall off; sequence; then we can start to see where the O.F.s line up–can see where we suddenly shift from O.F. on the top vs botton strand

Question 2

describe the SNP experiment

Answer 2

it was thought that bacterial and mammalian promoters could form tetraplex DNA, and that single-nucleotides polymorphisms would disrupt the formation of 4plex DNA, thereby diminishing its promoter activity. a non-mutated ssDNA gene of the promoter was tested against a strand with a GC switched, which disrupted the poly-G region (that forms tetraplex DNA)

Question 3

how can EtBr be used to separate circular DNA from linear?

Answer 3

EtBr can intercalate more into linear DNA than circular DNA (due to positive supercoiling) which will decrease the densitity of the linear DNA; when centrifuged on a Cs gradient, linear DNA will float at the top while circular DNA sinks to the bottom

Question 4

EtBr as an anti-trypanosomal drug

Answer 4

a 1mg/kg dose impairs mitochondrial replication; a 10mg/kg dose impairs nuclear replicationin parasite; can also damage host cell replication

Question 5

danourubicin mech

Answer 5

prevents replication and transcription, interfering with topoisomerase II and free rad production; has charactierstic toxicity: hair loss, bone marrow suppression; nausea, reversible but dose-dependent heart-damage

Question 6

how can alkylating agents be used in chemo?

Answer 6

alkylating agents produce mutations–>no issue for cells that replicate slow enough to catch the mutations; if cells cut corners when replicating, like cancer cells, mutations could lead to apoptosis or render the cell non-viable

Question 7

how can nitrogen mustard be used as an anticancer agent?

Answer 7

can first be converted to an inactive prodrug–by adding on a phosphate ring–>will be activated when the N-P bond is cleaved–>once cleaved the drug aldophosphamide is created in the liver and redistributed throughout the body–the tissues with high levels of aldehyde dehydrogenase can inactivate the xenobiotic and protect the cells; cancer expresses low amounts of ALDH so they cannot detoxify the xenobiotic and thus are subjected to alkylation which can create mutations