mRNA

[Whiteshoes]

TPR science workbook. pg534

Roman numeral question:

Which are true regarding protein synthesis in eukaryotic cells.

I. The mRNA is spliced before translation

There are other choices too but they're irrelevant to my question.

So I chose the answer without I. because I reasoned that mRNA is not spliced prior to translation but the Primary RNA is spliced to form the mRNA. I got it wrong.. Was my reasoning incorrect or is the answer choice worded incorrectly.

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[Whiteshoes]

nvm I was probably just over thinking it.

TPR science workbook. pg534

Roman numeral question:

Which are true regarding protein synthesis in eukaryotic cells.

I. The mRNA is spliced before translation

There are other choices too but they're irrelevant to my question.

So I chose the answer without I. because I reasoned that mRNA is not spliced prior to translation but the Primary RNA is spliced to form the mRNA. I got it wrong.. Was my reasoning incorrect or is the answer choice worded incorrectly.

 

[SaintJude]

No, I think you're right. I think their wording is not precise--and the MCAT test makers wouldn't be that sloppy.

Choice I should have read:
The precursor to mRNA is spliced before translation. OR "The RNA transcript is spliced before translation"

It is in the primary RNA transcript, the pre-mRNA, in which splicing out of introns occurs. The processing of hnRNA to mRNA occurs in the nucleus.

The failure to complete splicing of the primary RNA transcript & other processing in the nucleus will normally result in breakdown of the pre-mRNA.

 

[MedPR]

The question could be worded better, but pre-mRNA is still mRNA. Otherwise it would be called something other than pre-mRNA. For example, DNA is made of deoxyribonucleotides, but we don't call deoxyribonucleotides "pre-DNA" because it is incorrect to consider them to be DNA.

So, if you said "mRNA is not spliced before translation," then when is it spliced? Certainly not during, and not after translation. So it's not spliced at all? No, it is spliced prior to translation, it just happens to be called something different.

Another example would be this question:

True or false, inactive enzymes bind to cofactors/coenzymes to become active holoenzymes?

The answer is true. BUT by your pre-mRNA/mRNA reasoning, the answer is false because an "enzyme" that isn't bound to its cofactor is called an apoenzyme.

 

[SaintJude]

I see your point . But your enzyme question is worded correctly because by definition an "apoenzyme" is an "inactive enzyme".

The MCAT commonly tests what is necessary for a piece of RNA to become a mRNA.
a.) 5 Gcap is added, b.) poly A-tail is added. c.) introns must be removed.

All in all, I see your point and agree with you. I was just saying that MCAT tests aren't incorrectly worded, but your practice book may be.

 

[Temperature101]

No, I think you're right. I think their wording is not precise--and the MCAT test makers wouldn't be that sloppy.

Choice I should have read:
The precursor to mRNA is spliced before translation. OR "The RNA transcript is spliced before translation"

It is in the primary RNA transcript, the pre-mRNA, in which splicing out of introns occurs. The processing of hnRNA to mRNA occurs in the nucleus.

The failure to complete splicing of the primary RNA transcript & other processing in the nucleus will normally result in breakdown of the pre-mRNA.

I think you are overthinking the question..The wording is not that outrageous.

 

[MedPR]

That's true about apoenzymes.

I agree that it could've/should've been worded better. At least none of us will forget that pre-mRNA is spliced before it can officially be called mRNA!