TrueTears question thread

[monokekie]

umm. with regards to that DNA question, i got 28..

i assumed its double stranded since a gene would be in a helix shape. then there would be 15 neucleotides in each strand being linked by 14 bonds that could be hydrolysised. 14x2=28 then 28 molecules of water would be required.

this is my own interpretation of this question though.

[TrueTears]

umm. with regards to that DNA question, i got 28..

i assumed its double stranded since a gene would be in a helix shape. then there would be 15 neucleotides in each strand being linked by 14 bonds that could be hydrolysised. 14x2=28 then 28 molecules of water would be required.

this is my own interpretation of this question though.

Yeah it says COMPLETELY seperate the nucleotide itself.

So I did what you did, I thought it was double stranded so you will need 28 water molecules to seperate each nucleotide from the other nucleotides.

But then you need 2 water molecules to break the bond b/w phospate and deoxyribose and deoxyribose + base.

So theres 30 nucleotides, 2 x 30 = 60

so should be 60 + 28 = 88 water molecules.

But the answers have 89, which I assume they thought it was single stranded hence you need 29 water molecules to seperate all the nucleotides from each other.

How should I interpret this question?

[monokekie]

arhh.. !

its single stranded..

there are 30 neucleotides altogether,

then: there are 30 bonds between nitrogenbase and deoxyribose sugar
        and 30 bonds between sugar and phosphate groups (one for each neucleotide)
        and 29 bonds between the 30 neucleotides

i hope this makes sense   

[TrueTears]

arhh.. !

its single stranded..

there are 30 neucleotides altogether,

then: there are 30 bonds between nitrogenbase and deoxyribose sugar
        and 30 bonds between sugar and phosphate groups (one for each neucleotide)
        and 29 bonds between the 30 neucleotides

i hope this makes sense  

Yeap I know that, but how do you know if it is single / double stranded? That's what seems ambiguous to me.

[monokekie]

hmmmm....... yeah..... 

where does this question come from??

[TrueTears]

hmmmm....... yeah..... 

where does this question come from??

TSFX 09 paper. Q 6a) ii

[monokekie]

ohh.. no wonder... tsfx >_<!

Irena seems really hot on ambiguous questions...  

anyway.. hopefully i can figure it out tnite, in my dreams LoL

[Mao]

It's not so ambiguous if you google'd what 'gene' means.

A gene is a sub-unit of DNA, and it is double stranded

[TrueTears]

It's not so ambiguous if you google'd what 'gene' means.

A gene is a sub-unit of DNA, and it is double stranded

So answer should be 88 instead of 89?

[arthurk]

lol mao had same idea as me
google has all the answers:P
bit late isnt it truetears
2 am?

[Mao]

Wait, ignore previous. I think a gene is single stranded now.

=\ It's very ambiguous (I'm such a hypocrite)

[monokekie]

rofl.

i wish this type of questions will to appear too often on exams...

[TrueTears]

Alright thank you all!

[shinny]

From my experience, take base and base pairs to mean the same thing in terms of length of DNA. I don't see why anyone would want to talk in terms of both strands added together, that's just stupid. As for Mao's dilemma, it's probably more correct to say it's single stranded since only one side is actually transcribed and is the 'actual' gene.

[NE2000]

I think my bio teacher last year said something about us calling the DNA on the coding strand (non-template strand) the gene so yeah that should be right.

As for Mao's dilemma, it's probably more correct to say it's single stranded since only one side is actually transcribed and is the 'actual' gene.

Although a point of conflict here: according to my teacher it was the side that wasn't transcribed that is the 'actual' gene because this strand is complementary to the other strand just like the mRNA and the mRNA contains the codons and the codons make the gene.

Back to the question I can't imagine them meaning 30 bases in a gene to mean 15 bases on two strands. If they said there are a total of 30 bases on a double stranded piece of DNA then it is different. But still the question is ambiguous.