Acinar Cell Product

[mrmandrake]

Hey guys,

Quick question. In EK1001 Bio problem #617, it asks:

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Which of the following is NOT an acinar cell product?

A. lipid-digesting lipase
B. bond-breaking gyrase
C. peptide-hydrolyzing trypsinogen
D. neutralizing HCl

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My answer is D, since the stomach parietal cells produce this.
EK's answer is B.

I believe that the exocrine pancreas releases nucleases that break down DNA and RNA and that is why I did not pick B. Anyone see why B would be the correct answer because I can't see it. Thanks!

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[Isoprop]

i'm not exactly sure:

stomach parietal cells secrete HCl, so that's definitely an acinar cell product. nucleic acid gyrases afaik are not secreted but rather enzymes present inside the nucleus of the cell.

nucleases cut dna/rna, gyrases nick them to add/subtract coils. they aren't the same thing.

 

[mrmandrake]

So parietal cells of the stomach are a type of acinar cell? That would make sense to why I am wrong. Thanks.

 

[DrJD]

So parietal cells of the stomach are a type of acinar cell? That would make sense to why I am wrong. Thanks.

I do not know if the parietal cells are acinar cells, but I can tell you that they do not secret "neutralizing HCL"... The parietal cells secret straight up HCL... Hope that helps a little!

 

[Isoprop]

i would guess parietal = acinar because they do secrete HCl.

As far as "neutralizing" yeah the parietal cells afaik don't really neutralize (pH=7). but HCl does have the ability to "neutralize." so if the stomach had a pH>7 for some reason, the gastric acid would neutralize it. I think that word in there is suppose to throw you off.

 

[halekulani]

acinar cell = pancreatic cell
answer D is correct because the pancreas secretes bicarb to "neutralize HCL"

poorly worded answer stem

 

[mcnugget]

acinar cell = pancreatic cell
answer D is correct because the pancreas secretes bicarb to "neutralize HCL"

poorly worded answer stem

Yes...D. is a poorly worded answer

Acinar cells in your pancreas contain acidophillic zymogen granules in the apical portion of their cytoplasm...e.g's of these granules included: proteases (trysinogen, chymotripsinogen, etc..), RNAases, amylases, lipases....In addition, their other exocrine secretion consists of bicarbonate (which is responsible for neutralizing the acidic chyme that moves from the pylorus region of the stomach into the relatively less protected region of the small intestine, known as the duodenum). Bicarbonate is released in response to action of secretin (from the enteroendocrine cells of the duodenum) on the pancreas


So basically B. is wrong b/c the pancreas secretes RNAases...but not bond breaking gyrase (which acts on DNA...not RNA)

I hope this is not too confusing

 

[MattD]

acinar cell = pancreatic cell

ennnnnnnnkkkkkk try again

it's like the square/rectangle association... all pancreatic exocrine cells are acinar, but all acinar cells are not pancreatic exocrine.

 

[halekulani]

thanks for the clarification

i only wrote what was necessary to answer the question itself
for what they need to know for the mcat, i think they can assume acinar is analogous to pancreatic cell.

 

[MattD]

thanks for the clarification

i only wrote what was necessary to answer the question itself
for what they need to know for the mcat, i think they can assume acinar is analogous to pancreatic cell.

Well as long as you think it.....




it WAS a poorly worded question though. I think the intent of the question was to ask what chemicals were commonly SECRETED by acinar cells, and without overthinking it too much B makes sense as the answer. I'm not sure why they would call parietal cell product 'neutralizing' HCl, but HCl is an acinar product, so I'd have probably assumed that to be an ok choice. I'd have picked B. Of course, the problem with B is that while gyrase may not be secreted by acinar cells (to my knowledge anyway), it almost certainly is PRODUCED in acinar cells... They do replicate at some level after all. So does product = what is secreted, or simply what is produced by the cell?

I guess HCl COULD theoretically be considered neutralizing, if you ate a meal consisting of a bucketfull of lye washed down with a cold refresking KOH solution.....

 

[halekulani]

well i think you solved the answer there
gyrase is produced but not secreted by acinar cells

i think that's way too technical to expect test takers to know though :\