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[Unregistered] hi, i dont know if this will work but if so i have a few questions about living as a family at GND

[usmlee] hi

[Unregistered] hello

[Unregistered] wats going on

[usmlee] good

[Unregistered] where are you located? Im in USA

[docrosana] where in the us

[Unregistered] hi

[sanya] Hi guys,I'm new to this group, is this the place where the biochem chat is supposed to start?

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[erum] sanya yes

[usmlear] sorry got dc

[erum] me too

[dr_ashima] which college

[usmlear] ok,now lets begin

[erum] ok

[usmlethings] good let start it going

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[usmlear] steps in DNA replication?

[usmlear] 3..initiation,replication & termination

[erum] origin of replication seq is identified and bound by dna a protien

[usmlear] function of helicase & primase?

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[usmlear] ok

[erum] helicase breaks apart the two strands of dna

[usmlear] rt

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[erum] primase makes a rna primer

[usmlear] and pri..generates RNA

[usmlear] RNA primase bound to the starting DNA site.

[erum] why do we need a rna primer for dna replication

[erum] any one

[usmlethings] cos DNA polymerase cannot starit

[erum] rt

[usmlear] starting point for replication?

[usmlear] yes

[erum] dna polymerase can only extend a strand from 3- 5 prime end

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[erum] cannot start making it

[erum] so rna primer is needed

[usmlear] DNA poly.binds to the RNA primase, which indicates the starting point for the replication.

[usmlear] rt erum

[erum] rt

[usmlear] why new DNA synthesis in 5' -->3' direction?

[usmlear] so that DNA polymerase can only travel on one side of the original strand without any interruption..this strand is called lagging strand

[erum] bcuz dna polymerase 3 start making it from 3 'end

[usmlear] leading starnd?

[usmlear] it is 3'-->5'

[usmlethings] What calss of drugs inhibit Gyrase?

[sanya] Quinolones

[erum] read it from 33'to 5'

[erum] make it 5' to 3'

[usmlethings] Quinolones right

[usmlear] agree

[erum] what removes the rna primer

[erum] quinolone

[usmlethings] DNA poly 1

[erum] rt

[erum] what r okazaki fragments

[usmlethings] laging strand DNA

[erum] the pieces of lagging strand

[erum] rt

[sanya] Short fragments of dna which form the lagging strand

[erum] what joins these pieces?

[erum] rt usmlethings sanya

[usmlethings] Lygase

[sanya] DNA ligase

[usmlear] short fragment of DNA created on the lagging strand during DNA replication.

[erum] rt

[erum] usmlear rt

[usmlear] ok

[erum] so we r left w/ 1 leading strand and 1 complete lagging starnd

[sanya] In eukaryotes the leading strand is made by which polymerase?

[usmlear] rt

[usmlear] III

[usmlear] sorry..III for pro.

[erum] poly delta

[sanya] right

[erum] dna polymerase delta

[erum] what r topoisomerase

[erum] why r they important

[sanya] prevent the positive supercoiling

[usmlethings] they make niks in DNA strand to un coil it

[usmlear] rt

[sanya] because it can inhibit the Dna replication

[erum] rt and isert -ve super coiling unwinding dna

[usmlear] which polym. for DNA repair?

[usmlethings] whch topoisomerases make 2 niks and which make only one nick?

[erum] certain anti cancer drugs blocks thiese enzyme names?

[sanya] etopside

[erum] rt and teniposide

[usmlear] ok

[erum] dna gyrase 1

[erum] for 2 cuts

[erum] topo 1 i cut

[usmlear] Conditions in which DNA repair is not possible?

[usmlethings] Yes gyrase(Topo II) make 2 cuts Topo I make only one cut

[erum] xeroderma pigmentosum

[sanya] Deficiency of excision endonuclease

[usmlear] ok,here is the defi of DNA repair enz

[usmlear] what else?

[erum] rt that ts called xeroderma pigmentosum

[usmlear] some cond like..tum suppresor gene inactivated

[erum] its spontaneous , by chemicals , heat

[usmlear] mutation/deletion

[erum] drugs

[usmlear] rt

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[usmlear] Li Fraumani syndrome

[erum] rt p 53 suppression

[usmlear] yes

[usmlear] ataxia telen

[sanya] What is excision endonuclease, is it repair enzyme or a recognition enzyme?

[erum] also ataxia telangectasia and brca gene

[usmlear] rt

[usmlethings] excision

[usmlethings] Is repair

[usmlear] what we do in PCR?

[sanya] Its recognition enyme, the repair enyme is DNA polymrease

[erum] it recognises and cut the damaged part polymerase build that part

[erum] ligase closes the ends

[usmlethings] Making targeted DNA strand in numbers

[usmlear] PCR is done by...separating the DNA into two strands and incubating it with oligonucleotide primers and DNA polymerase. It can amplify a specific sequence of DNA by as many as one billion times

[usmlear] rt

[erum] making copies of dna part in large numbers

[usmlethings] What ensyme is needed to make cDNA?

[usmlear] reverse trans.

[erum] c = a?

[usmlethings] Reverse Transcriptase

[usmlear] complimentary

[erum] ok

[erum] reverse transciptase

[usmlear] this enz present in certain viruses..like?

[erum] hiv

[usmlear] oncogenic..like retrov.

[usmlear] rt

[usmlethings] What histone does not include in nucleosome?

[sanya] Guys I've read only the 1st and 2nd chapters from Kaplan biochem old edition(2004), does the new edition have PCR etc in the 1st or 2nd chapters or are you just discussing in general.

[erum] h1

[sanya] H1

[usmlethings] yes h1

[usmlear] sorry sanya..some Qs r in general..pl. ask from 2 chapters

[usmlear] u ask sanya

[usmlethings] sanya go ahead

[erum] why others r quite?

[sanya] Not a problem, just making sure my book is not too outdated

[usmlear] what is deamination..example?

[sanya] cytosine changing to uracil

[usmlear] rt

[usmlear] which drug deaminates inside the body?

[erum] cyto to uracil

[sanya] Where does trancription occur and where does translation occur?

[erum] cytarabine

[usmlear] cytarabine

[usmlear] used in leukemia

[usmlear] rt

[sanya] Reason for drug resistance in cancers

[usmlethings] trascription-Nuleus, Translation ribosome

[erum] trans in nucleus translation in cytpo

[usmlear] what is Chargaff's rule?

[erum] cytoplasm

[sanya] right

[erum] a%=t c+g

[erum] c=g

[erum] a=t

[sanya] The A=T's and G=C's

[usmlear] rt

[erum] so purines = pyramidines

[usmlear] what is Z-DNA?

[sanya] left hand helix

[usmlear] Z-DNA--> A form of DNA in which the double helix twists in a left-hand direction, thus producing a zigzag appearance..biological function unknown

[usmlear] rt sanya

[erum] left sided helix ww/ cg rich

[usmlear] rt

[sanya] What is the size of euchromatin?

[usmlear] ?

[erum] 30 nm

[sanya] I am not very clear about this, i thought it is 10nm and hetreochromatin is 30nm

[usmlear] what is renaturation..what r the uses?

[usmlear] u maybe rt sanya..bec euchr is condenesed form

[erum] hetero is tightly coiled so should be smaller

[usmlethings] hetero in the condensed

[usmlethings] hey guys gotta go keep on going see ya next time! bye

[usmlear] euchr. is uncoiled form..so should be smaller?

[usmlear] thx usmlethings

[usmlear] see u tomo.

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[ypoornima] euchromatin is uncoiled form,but accounts for 90% of the chromatin

[usmlear] renatu. is the process by which proteins or complementary strands of nucleic acids re-form their native conformations..used is southern blot & pcr

[ypoornima] only 10%is actively ranscribed

[sanya] Think I will look it upand let you know tomorrow.

[usmlear] ok yp

[usmlear] thx

[ypoornima] u r welcome

[usmlear] thx everybody..we finished today's topics..for tomorrow..

[usmlear] Transcription and RNA Processing & The genetic Code Mutations, and Translation

[sanya] Are you guys reading HY too?

[usmlear] not me sanya

[sanya] OK

[erum] me niether

[usmlear] mole is good in kap

[usmlear] ok,guys..bye

[erum] ok

[sanya] How about starting at 10 sharp tomorrow coz' there's a lot to cover in those 2 chapters

[usmlear] see u all tomorrow at 10.00pm

[erum] bye all

[usmlear] we can start at 10.00

[sanya] Bye and Thanks everybody!

[usmlear] Ok,Bye