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Old 04-10-2011
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DNA Molecular biology ....transcription

A gene encodes a protein with 150 amino acids. There is one intron of 1,000 bps,a 5`-UTR of 100 bp, and a 3 -UTR of 200 bp.

IN the final processed mRNA how many bases lie between the start AUG codon and final termination codon...

a) 1,750
b) 659
c) 555
d) 450


WHAT IS BP?????

AND THERE IS NO EXPLAINATION OF THIS TYPE OF QUESTION IN KAPLAN NOTES....

SO WUTS ANSWER....
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Old 04-10-2011
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BP stands for base pair

Only exons code for amino acid sequence in protein. This exons lie between AUG start codon and terminal codon in mRNA (not between the 5'UTR and 3'UTR) . There is no intron in mRNA anymore. Each amino acid is coded by a codon consisting of 3 nucleotides, so if there is 150 amino acids, there must be 450 nucleotides, meaning 450 base pairs.
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Old 04-11-2011
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Default D

So .. this Question is very good explaned in KL- David Seastones lectures.
the main thing here to know is that 3 BP-s can give 1 amino acid, So if in the final protein are 150 Amino acids this means that final processed mRNA contains 150 * 3 = 450.

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Old 04-11-2011
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it means that INTRON and UTR are nothing to do with question...

simply see how many amino acids and multiply with 3 that will be the final answer...

THANKS FOR EXPLANATION


CAN SOME ONE PLZ POST MORE QUESTION LIKE THIS????
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Old 04-11-2011
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This Q is from KLN Biochemistry Page 44 I haven't seen another, any kind of this question ever
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Old 04-11-2011
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Quote:
Originally Posted by beka-CTS View Post
This Q is from KLN Biochemistry Page 44 I haven't seen another, any kind of this question ever

ok

have u done with step1 ??

have u any skype id or email so i can keep intouch wid u

regards..
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Old 04-11-2011
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Quote:
Originally Posted by ikrimachoudry View Post
A gene encodes a protein with 150 amino acids. There is one intron of 1,000 bps,a 5`-UTR of 100 bp, and a 3 -UTR of 200 bp.

IN the final processed mRNA how many bases lie between the start AUG codon and final termination codon...

a) 1,750
b) 659
c) 555
d) 450


WHAT IS BP?????

AND THERE IS NO EXPLAINATION OF THIS TYPE OF QUESTION IN KAPLAN NOTES....

SO WUTS ANSWER....
d: 450
BP is base pair
1 amino acide is 3 base pair
so 150 AA x 3 = 450

all the other number is just to make us crazy!!
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Old 04-11-2011
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waoooo

tinhi thanks the other numbers are just diverter...trap...
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Old 04-11-2011
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Default question number 2

a. ATGCAA---->ATGTAA

b. ATGAAA---->GTGAAA

c. TATAAG----->TCTAAG

d. CTTAAG------>GTTAAG

e. ATGAAT------>ATGCAT


the options above represent mutations in DNA with base changes indicated in bold
for each mutation described in this question below,choose the most closely related sequence change in options above...

1) NONSENSE MUTATION

2)MUTATION decreasing the initation of transcription


answers
1) a
2) c


this is from kaplan notes....

IT ALSO SAYS THAT DONT THINK ABOUT DISTRACTOR< b>

THE QUESTION IS NOT ABOUT TRANSLATION....


CANT UNDERSTAND LAST ARGUEMENT WHAT BOUT IF ITS BOUT TRANSLATION
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Old 04-12-2011
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No i havn't yet. I'm diong biochemistry right now.
that's why i knew this question. that's not a problem.
my skype id is: midsomer_murders

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Old 04-12-2011
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Quote:
Originally Posted by ikrimachoudry View Post
a. ATGCAA---->ATGTAA
b. ATGAAA---->GTGAAA
c. TATAAG----->TCTAAG
d. CTTAAG------>GTTAAG
e. ATGAAT------>ATGCAT
the options above represent mutations in DNA with base changes indicated in bold - for each mutation described in this question below,choose the most closely related sequence change in options above...
1) NONSENSE MUTATION
2)MUTATION decreasing the initation of transcription
answers
1) a
2) c
this is from kaplan notes....
IT ALSO SAYS THAT DONT THINK ABOUT DISTRACTOR
THE QUESTION IS NOT ABOUT TRANSLATION....
CANT UNDERSTAND LAST ARGUMENT WHAT IS iT ABOUT IF ITS not ABOUT TRANSLATION?
The first one is about translation (new stop codon)
The second one is about transcription (change in tata box)
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Old 04-12-2011
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Quote:
Originally Posted by Mondoshawan View Post
The first one is about translation (new stop codon)
The second one is about transcription (change in tata box)
can you explain this please... i dun c how ur getting the stop codon in the first part.
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Old 04-12-2011
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5`ATGTAA 3` this is coding strand

5`TTACAT3` will be the template strand for it

5` AUGUAA 3` will be mRNA strand


UAA ----> is stop codon i.e non sense mutation..


there are three nonsense mutations (codons)

UAA---> you are away

UAG---> you are gone

UGA----. you go away


hope u are clear now
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Old 04-12-2011
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Quote:
Originally Posted by ikrimachoudry View Post
5`ATGTAA 3` this is coding strand

5`TTACAT3` will be the template strand for it

5` AUGUAA 3` will be mRNA strand


UAA ----> is stop codon i.e non sense mutation..


there are three nonsense mutations (codons)

UAA---> you are away

UAG---> you are gone

UGA----. you go away


hope u are clear now
oooo ok!!! thank u so much
yes, its clear now
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Old 05-18-2011
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Default Template/coding strand of DNA in questions

I cant get when they give template strand, when coding strand in questions. Regarding question 2 that was discussed above in answers they comment that "TAA will be transcribed to UAA in the mRNA". That is possible only if they give coding strand in question. But I thought if there is nothing mentioned in the question, we should consider the given sequence a template strand written in 5' to 3' direction. And if we consider 5'-TAA-3' a template sequence, it should be transcribed to 3'-AUU-5' (not UAA).

Likewise in 11 question's answer. They say ATC and ATT both code for ile (AUC and AUU). It's also true if DNA sequences given in question represent coding strand.

I'm so confused, please, help me, folks!!!!!!!!

Last edited by dr.rabbit; 05-18-2011 at 09:35 AM.
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Old 02-14-2013
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Default Can't understand what the Part 2 of the second Q is trying to ask!!

Quote:
Originally Posted by INCOGNITO View Post
a. ATGCAA---->ATGTAA

b. ATGAAA---->GTGAAA

c. TATAAG----->TCTAAG

d. CTTAAG------>GTTAAG

e. ATGAAT------>ATGCAT


the options above represent mutations in DNA with base changes indicated in bold
for each mutation described in this question below,choose the most closely related sequence change in options above...

1) NONSENSE MUTATION

2)MUTATION decreasing the initation of transcription


answers
1) a
2) c


this is from kaplan notes....

IT ALSO SAYS THAT DONT THINK ABOUT DISTRACTOR< b>

THE QUESTION IS NOT ABOUT TRANSLATION....


CANT UNDERSTAND LAST ARGUEMENT WHAT BOUT IF ITS BOUT TRANSLATION


Could anybody explain what in the whole galaxy "MUTATION decreasing the initation of transcription" means

and also it's equally baffling answer!!
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Old 02-14-2013
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Quote:
Could anybody explain what in the whole galaxy "MUTATION decreasing the initation of transcription" means

and also it's equally baffling answer!!
Basically means it's a mutation in the promoter region.. If there's a mutation in the TATAA box or CAAT box or GC rich region, then the transcription initiation complex may not form.. Likewise if you a mutation in the enhancer region then initiation complexes will form very slowly and result in a decreased number of transcriptional product and end proteins.
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