chiddler

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Most bacterial cells and human cells are alike in the ability:

*A. to produce ATP via ATP synthase
B. the chemical composition of their ribosomes

The chemical composition! I spent a moment trying to understand what is meant by "chemical composition". I concluded that this term relates chemistry moreso than biology and therefore probably refers to the C, N, O, H - the main components of ribosomes at the chemical level.

Apparently this is the incorrect interpretation. What is meant by chemical composition?

i hate these questions...
 

MedPR

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Most bacterial cells and human cells are alike in the ability:

*A. to produce ATP via ATP synthase
B. the chemical composition of their ribosomes

The chemical composition! I spent a moment trying to understand what is meant by "chemical composition". I concluded that this term relates chemistry moreso than biology and therefore probably refers to the C, N, O, H - the main components of ribosomes at the chemical level.

Apparently this is the incorrect interpretation. What is meant by chemical composition?

i hate these questions...
Ha I remember this question! Remember that the inner mitochondrial membrane (where the ATP synthase is) is a product of prokaryotic plasma membrane invagination. So you expect the prokaryote plasma membrane to be just about equivalent to the inner mito membrane in eukaryotes.

Euk = 40S and 60S (80S) ribosome
Prok = 30S and 50S (70S) ribosome

So presumably the prokaryotic rRNA sequence is different than the eukaryotic sequence.
 
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chiddler

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crap. that could be it...

that is way too detailed though. rRNA sequence. but predictable...

:(

lame question...
 

MedPR

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crap. that could be it...

that is way too detailed though. rRNA sequence. but predictable...

:(

lame question...
What do you mean too detailed? I think we're supposed to know that our RNA are different and that rRNA contributes to RNA structure!
 

Morsetlis

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It's not lame, you're expected to think that "bacteria and humans both make ATP... by similar ATP synthase mechanisms, but protein synthesis from mRNA probably uses different mechanisms, and rRNA makes ribosomes, and rRNA are different..."
 
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chiddler

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What do you mean too detailed? I think we're supposed to know that our RNA are different and that rRNA contributes to RNA structure!
i meant just based off our biology books, we know that there is 70s and 80s but we don't know how they differ. Could it not be possible that the RNA sequence is conserved and the protein portion differs?
 

MedPR

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i meant just based off our biology books, we know that there is 70s and 80s but we don't know how they differ. Could it not be possible that the RNA sequence is conserved and the protein portion differs?
I guess, but you should know about ATP synthase enough to know its the right answer.
 
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chiddler

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i realize the futility of arguing this.

my reasoning was that bacteria have diversity in energy production. they can be aerobic or anaerobic and all sorts of uncommon colors thereof.

eukaryotes perhaps without exception all use a very similar system of energy production.
 

Morsetlis

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Ok, what would you use to treat a bacterial infection, Oligomycin (ATP synthase inhibitor) or Streptomycin (30S inhibitor)?

That's the whole point.
 

DrRichand1

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Fun Fact:

Don't forget that mitochondrial ribosomes are not 80s but r similar to prokaryotes 70s. so drugs that affect bacterial ribosomes will also have neg affects on eukaryotes.
 

ridethecliche

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I went with ribosomes to answer that one too because I thought that the code was the same.

However, don't bacteria use slightly different RNA?

There isn't a chemical difference between having 70s vs 80s. They're both made of the same things. I.e. rRNA.

It's a structural difference.
 
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chiddler

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which is why i still think this question is a cheap shot.
 

ridethecliche

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I agree.

I guess this is the distinction between okay answer and best answer.

Probably bigger difference in rRNA than in atp synthase. So the best answer wins.

Welcome to the bloody farking mcat.