EK Biology Genetics Qs

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Hexon

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173) i understand that procaryotes require

1) proper concn of methionine
2) amino acid formylase to carry out formylation reactions

but why doesn't it require 'an AUG start/stop codon'?
my rationale was that you'd need AUD to start the whole entire protein synthesis wouldn't you??

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So I don't have this full question for reference, but what in the world are you asking? Are you getting confused with the wobble mechanism where all 3 base codons don't have to be exactly AUG??? There's no such this as AUD...The initiation can occur with UUG or GUG...
 
If I'm reconstructing this correctly, the question asks "what's required for translation in prokaryotes?" and the options are
1) proper concentration of methionine
2) amino acid formylase to carry out formylation reactions
3) an AUG start/stop codon

As above poster noted GUG and UUG are also used as start codons in prokaryotes so option 3) 'an AUG start/stop codon' is not absolutely REQUIRED (sufficient but not necessary).

On that note, you'll find similar questions on the MCAT. When you see "required" in the stem, be very aware of the distinction between sufficient and necessary.
 
So I don't have this full question for reference, but what in the world are you asking? Are you getting confused with the wobble mechanism where all 3 base codons don't have to be exactly AUG??? There's no such this as AUD...The initiation can occur with UUG or GUG...

sorry i did mean AUG lol not AUD;)
the whole question:

'prokaryotes require which of the following parameters in order to synthesize protein?
1) proper concn of methionine.
2) an amino acid formylase to carry out formylation reactions.
3) an AUG start/stop codon.

i picked all three but the answers said only 1 and 2 were correct; my impression was that you needed an AUG start codon to commence synthesis of protein:p

@paul411
ah, i see, thanks for your help:)

thanks to you, too danlee07:)
 
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sorry i did mean AUG lol not AUD;)
the whole question:

'prokaryotes require which of the following parameters in order to synthesize protein?
1) proper concn of methionine.
2) an amino acid formylase to carry out formylation reactions.
3) an AUG start/stop codon.

i picked all three but the answers said only 1 and 2 were correct; my impression was that you needed an AUG start codon to commence synthesis of protein:p

@paul411
ah, i see, thanks for your help:)

thanks to you, too danlee07:)

AUG is not a stop codon
 
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