perfectcube
Forum Newbie
Topics: 1
Posts: 13
|
Hey guys
I have a simple question.
Is the 30 nm fiber euchromatin or not?
According to KLN it is. According to Dr Raymon it is not.
|
| unique1
InGodITrust
Topics: 19
Posts: 1,410
|
It is not. Can you please give the referance where does the Kaplan say it is ?
___________________
I can't change the direction of the wind, but I can adjust my sails to always reach my destination.
|
| silver
Forum Guru
Topics: 21
Posts: 771
|
This is the explanation that the Kaplan people themselves have given regarding this. You're not the only one confused about this. When they realized, they gave this explanation:-
Please be advised that in the first chapter, Nucleic Acid Structure and Organization, within the sub-topic: Organization of DNA, the lecturer is discussing the packing and organization of DNA. The size of euchromatin may vary. When it is not tightly packed it may be 10 nm thick. In highly packed form it may be 30 nm thick. The Histone H1 is responsible for tight packaging of the neucleosomes. The more loosely packed Euchromatin is the more sensitive it is to the nuclease. The 30 nm euchromatin may undergo higher order packaging and form highly condensed Heterochromatin. The 30 nm neucleosomes is referred to as “Heterochromatin” in the lecture. Please note that the 30 nm fiber may exist as either euchromatin or heterochromatin depending upon the level of packaging.
___________________
Every disaster hides an opportunity.
|
| perfectcube
Forum Newbie
Topics: 1
Posts: 13
|
Interesting...
Lippincott's doesn't clarify it either.
EDIT Neither does Stryer. I guess I'll leave it to that.
Another post I've just found on the subject
http://www.prep4usmle.com/forum/thread/44788
"if anyone else is also using kaplan recorded lectures, please note an error in the biochem (i believe third tape). he states that the 10nm beads on a string is euchromatin, whereas 30nm compacted with H1 protein is heterochromatin. most other resources state that 30nm chromatin is euchromatin as well. as a matter of fact, i've found that 90% of euchromatin is actually 30nm, which is easily converted to 10nm where nucleosomes can separate the DNA for processing. heterochromatin is for higher than 30nm chromatin degree of packing."
Edited by perfectcube on 07/21/07 - 12:20 AM
|
| mytime
Kick my butt!
Topics: 39
Posts: 3,174
|
The explaination provided above by Perfectcube is actually what is correct. 30nm is a euchromatin too 90% of euchromatin is inactive(30nm). Only 10% active. Hence only 10% transcribes....that is ur 10nm opening up to give u ur templates i guess.
|
| fudoc_20
Forum Newbie
Topics: 3
Posts: 45
|
30 nm fiber is EUCHROMATIN and when it is associated with scafolding protein it becomes abit dense heterochromatic !
|
| Ig F
Forum Elite
Topics: 3
Posts: 431
|
___________________
i m not perfect but i wanna get close to it......
|
| janaki
Forum Senior
Topics: 15
Posts: 99
|
it also says in first aid that 30nm fiber is euchromatin
|
|
| |
| | | | | | | | |
