DNA Sequencing

[MedPR]

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Think we need to know different DNA cleaving agents and their specific cleaving activity? For instance chymotrypsin cleaves proteins at the carboxyl side of Phe, Tyr, and Try?

 

[pfaction]

TPR Orgo specifically states not to know this, but knowing it clips at the carboxyl side I think will come in handy.If you can come up with a generalized version I don't see why not, just like everyone says oh dont memorize amino acids, you kind of have to.

 

[SaintJude]

That's not mentioned in Kaplan. In general, Kaplan emphasizes site of production, site of function and function.
So all it says for chymotrypsin is that it is secreted as a zymogen in the pancreas. And then it "hydrolyzes specific peptide bonds" in the small intestine. That's it.

The level of detail you described in your post could only come up in a passage-based question. Not discrete.

 

[MedPR]

Ok thanks. TBR has a relatively long list along with their specific sites of cleavage. DNA sequencing is pretty cool, but the example TBR gives (which is probably a pretty simple one) is pretty damn hard.

 

[411309]

is this in TBR bio book 2? i never read that, i tried reading the first chapter and was like wtf? lol.

 

[MedPR]

is this in TBR bio book 2? i never read that, i tried reading the first chapter and was like wtf? lol.

Orgo book 2, the very end of the amine (or maybe it's the "Nitrogen") chapter.

 

[Class1P]

DNA cleaving agents? NO you should not have to know anything about those for the MCAT.

Are you thinking of stuff like EcoR1? which cleaves at certain sequences? you shouldn't have to know that. you may have to just know that there are enzymes whose specific purpose is to cleave specific sequences of bases.

It would be cruel to make somebody memorize different DNA cleaving agents. There are hundreds.

You need to know what would put 2 strands together, I think. (ligase)

 

[pfaction]

Exonucleases and restriction clip at palindromes and specific sites, and ligases join them back up. Just spurtin' out facts here. Gyrase is not found in humans, it serves to supercoil DNA whereas we have chromatin. Topoisomerase clips DNA strands to prevent supercoiling when Helicase splits up the DNA in Euk's.

 

[mcloaf]

Exonucleases and restriction clip at palindromes and specific sites, and ligases join them back up. Just spurtin' out facts here. Gyrase is not found in humans, it serves to supercoil DNA whereas we have chromatin. Topoisomerase clips DNA strands to prevent supercoiling when Helicase splits up the DNA in Euk's.

Almost. Exonucleases are not site specific, they just chew away at either the 5' or 3' end of exposed DNA (exo = out). You are talking about endonucleases, aka restriction enzymes, which cut at specific sites within a strand of DNA.

 

[1TB4RKSB4CK]

Good to know. Bumping just in case anyone is at this section and thought that those few pages were absolutely absurd.

 

[sps27]

Think we need to know different DNA cleaving agents and their specific cleaving activity? For instance chymotrypsin cleaves proteins at the carboxyl side of Phe, Tyr, and Try?

Thanks Johnny! Yes I have read that too. I think it is good nugget to know. Yes, I know.....It is taking me 3 days just to revise those 2 chapters on Genetics and Exp of Genetics from TBR. But I think it is well worth the effort.....