Login

Join for Free!
112474 members


A quick Question...

Discussion of all aspects of biological molecules, biochemical processes and laboratory procedures in the field.

Moderator: BioTeam

A quick Question...

Postby jayson » Tue Nov 29, 2005 8:57 pm

I have a quick question (it was on the test)

There is a nucleic acid consisting of

Adenine = 20%
Thymine = 25%
Guanine = 35%
Cytosine = 20%

Describe the nucleic acid, and its structure.



Basically,okay you know how in a DNA Adenine and Thymine quantities are suppose to be the same, along with Guanine and Cytosine. But here in this nucleic acid, they are all different. SO what kind of nucleic acid is it ?

I wrote "It is DNA, but some of the nucletides are missing and there could be severe mutation."

But some people in my class told me that they wrote RNA, which I did think of as the answer but it wouldn't make sense since RNA has Uracil. I was wondering how would you guys identify this "nucleic acid"
Last edited by jayson on Tue Nov 29, 2005 9:40 pm, edited 1 time in total.
User avatar
jayson
Garter
Garter
 
Posts: 27
Joined: Sun Nov 27, 2005 4:55 am

Postby sdekivit » Tue Nov 29, 2005 8:59 pm

i don't understand this question :s
sdekivit
King Cobra
King Cobra
 
Posts: 586
Joined: Sat Jul 30, 2005 7:16 pm
Location: holland

Postby mith » Tue Nov 29, 2005 10:12 pm

maybe the dna strand has "sticky ends" ends which do not have complements.
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr
User avatar
mith
Inland Taipan
Inland Taipan
 
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN


Postby Jennifer » Wed Nov 30, 2005 1:39 am

The N.A. is probably just single stranded.
~*Jennifer*~
User avatar
Jennifer
Garter
Garter
 
Posts: 20
Joined: Mon Nov 28, 2005 10:16 pm
Location: Canada! :)

Postby Terry K. » Wed Nov 30, 2005 1:42 am

I'll bet it's a bacteria/virus of some sort because most of the time either of these two don't have equal percentages of complementing base pairs.
Saying that any two humans are exactly alike is like saying republicans have morals
Terry K.
Death Adder
Death Adder
 
Posts: 96
Joined: Mon Oct 24, 2005 1:42 pm
Location: Myerstown, PA

Postby canalon » Wed Nov 30, 2005 2:01 am

Terry K. wrote:I'll bet it's a bacteria/virus of some sort because most of the time either of these two don't have equal percentages of complementing base pairs.


DNA virus, and bacteria have regular double stranded DNA so I don't really understand your comment.

RNA was also what first came to my mind, but jayson argument against it seem quite right to me. So single stranded DNA, but with that clues I don't really see what we can deduce anymore about structure (probably some secondary structure to stabilize this but...)
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)
User avatar
canalon
Inland Taipan
Inland Taipan
 
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Postby jayson » Wed Nov 30, 2005 2:10 am

So its a single stranded DNA ?

Man that just pisses me off. Lost four good marks right there. When I lose makes in BIO it hurts deep within. I know this stuff inside out, but always these small things mess me over.

What are the possible advantages of SS DNA over double helix that an organism would choose to have SS DNA ?
Last edited by jayson on Wed Nov 30, 2005 4:30 am, edited 2 times in total.
User avatar
jayson
Garter
Garter
 
Posts: 27
Joined: Sun Nov 27, 2005 4:55 am

Postby canalon » Wed Nov 30, 2005 4:23 am

Beats me, It's the only things that fits the 2 basic facts:
- DNA because of thymine, not Uracil
- Single stranded because otherwise there would be equal amount of A+T and G+C

But except if you really want to talk about the very rare case of non classical appariements between base I do not have the slightest idea what else it can be. But be sure to tell us the answer when you know it, I am interested. And I may be wrong.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)
User avatar
canalon
Inland Taipan
Inland Taipan
 
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Postby jayson » Wed Nov 30, 2005 4:39 am

Seems like the answer was single stranded Dna.

Where do you find ssDNA ? What are the possible advantages of having ssDNA as oppose to double helix, anyone know. Thanks in advance.
User avatar
jayson
Garter
Garter
 
Posts: 27
Joined: Sun Nov 27, 2005 4:55 am

Postby canalon » Wed Nov 30, 2005 4:48 am

Ooops I was wrong, ssDNA viruses do exist (But I am really not interested in viruses, you need to understand their host to understand how they work, and then it's complicated for me, I prefer bacteria:wink:). So it could be the source of your molecule. As for the advantage... no idea. More compact? result from their rolling circle replication? anything else? Maybe victor our virus specialist could help.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)
User avatar
canalon
Inland Taipan
Inland Taipan
 
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Postby krusaider » Wed Nov 30, 2005 4:37 pm

ssDNA viruses exist ofcourse. eg, phage M13 used as a cloning vector. DNA is cyclic and always of same strand i.e. molecules from different virions do not form double helix on annealing together .Direction of the strand in all virions is same 5'-3' or they other way. Advantage :me thinks to get packaged in the small phage head.
FISICULTURE
User avatar
krusaider
Garter
Garter
 
Posts: 8
Joined: Tue Nov 29, 2005 11:50 am

Postby MrMistery » Wed Nov 30, 2005 8:55 pm

yeap, there are a lot of single stranded DNA viruses. And i agree that this was the answer the teacher probably wanted. There are 2 kinds of ssDNA viruses:
-when DNA is linear(example: phi M13)
-when DNA is circular(example: phi X174-host E.coli*for patrick*)

I don't know what the advantage of having such a type of genetic material is, maybe it is "cheaper" in energy to make or easier to infect, but a very important thing for us scientists is that they show the evolution of DNA from RNA, by having this "primitive" kind of DNA
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)


Return to Molecular Biology

Who is online

Users browsing this forum: No registered users and 1 guest

cron