IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: *Hope* on April 18, 2010, 06:23:17 am
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Hey guys!!
I was wondering if anybody knows what is meant by partial denaturing of enzymes??
there are some answers in the mark scheme that include these answers and it seems I can't find it in the syllabus.
So if anybody knows it, I will be thankful :D
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please anybody??
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AS or A2
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oh As level
srry forgot to mention
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Hey guys!!
I was wondering if anybody knows what is meant by partial denaturing of enzymes??
there are some answers in the mark scheme that include these answers and it seems I can't find it in the syllabus.
So if anybody knows it, I will be thankful :D
http://www.s-cool.co.uk/alevel/biology/biological-molecules-and-enzymes/enzymes.html
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http://www.s-cool.co.uk/alevel/biology/biological-molecules-and-enzymes/enzymes.html
http://www.biology-online.org/biology-forum/about250.html
Umm, I understand you are asking what happens if we change the temp or pH?
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Guys am also confused about the chromatids, chromosomes and the number of DNA molecules present
Also do u have any idea of what are histones and if they are in the syllabus?? ???
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we don't have histones in the syllabus....but just for ur knowledge, remember the DNA wind itself around proteins called histones...
2 strands of DNA make a chromosome....1 Strand of DNA is a chromatid
clear?
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but isn't a chromatid a chromsome?
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but isn't a chromatid a chromsome?
2 chromatids make one chromosome
1 chromatid is 1 DNA strand wound on a histone
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ok can u check nov06 p1 q19 and explain
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yaa well
8 chromosomes= 16 chromatids(or 16 strands of DNA)
At the end of interphase, this value doubles....cuz replication take place in Synthesis phase of interphase...
so from 8 chromosomes, there will be 16...and so from 16 chromatids it will double to 32
But yet again the catch here is the no of DNA molecules(1 molecules has 2 strands of DNA), so what they intend to ask is for the no of chromosomes, not chromatids....
which is 16
Hence C
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clear?
Why do Indians always choose to use that word??
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Why do Indians always choose to use that word??
patent :P
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ok Thanks
+rep
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ok Thanks
+rep
u still haven't got it...have you?
I'll sent you some links if u need
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u still haven't got it...have you?
I'll sent you some links if u need
ok the truth is am kinda still confused cuz in the book they say at the interphase, after DNA replication, the chromosome has 2 DNA molecules so it means that before DNA replication, each chromosome has 1 DNA molecule. But any wayz some links from u will help insA ;)
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http://www.youtube.com/watch?v=s9HPNwXd9fk
watch this
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let me give it a try,
When a cell in not replicating, in interphase stage that is, It has 46 chromatins. these are long and thin and are not easily visible. Each Chromatin is one strand of D.N.A. So when the cell is receives signals to divide, each D.N.A molecule (each Chromatin) replicates and forms two D.N.A helices one in each of two chromatids joined at the centromere (so each chromatin splits in two chromatids). Each chromatid contains an identical copy of D.N.A and two sister Chromatids (that is containing the same D.N.A) joined at the centromere form a chromosome. So each chromosome contains two chromatids each with a D.N.A helix making each Chromosome to have 2 D.N.A helices.
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let me give it a try,
When a cell in not replicating, in interphase stage that is, It has 46 chromatins. these are long and thin and are not easily visible. Each Chromatin is one strand of D.N.A. So when the cell is receives signals to divide, each D.N.A molecule (each Chromatin) replicates and forms two D.N.A helices one in each of two chromatids joined at the centromere (so each chromatin splits in two chromatids). Each chromatid contains an identical copy of D.N.A and two sister Chromatids (that is containing the same D.N.A) joined at the centromere form a chromosome. So each chromosome contains two chromatids each with a D.N.A helix making each Chromosome to have 2 D.N.A helices.
thanks...that ws well explained...unlike mine...AS has taken a toll on me
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thanks...that ws well explained...unlike mine...AS has taken a toll on me
no problem, lol its happens to all of us! i'm so tired of studying right now, its gotten to a point i just want to get it over with and enjoy my summer!!