1 short BIOLOGY QUESTION

[joey2007]

When compared to ribosomes in free polyribosomes in the cytosol, rough ER-bound ribosomes have?

a) different large and small subunits
b) the same large and small subunits
c) different large subunits but the same small subunits.
d) different small subunits but the same large subunits.

Anyone pleae help me? I put B for this one!!! I would thanks a dozen times.......

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[zuma35]

I also think it's B.

 

[MTD52]

I have never heard of differences between subunits, other than those of Eukaryotes and Prokaryotes. I'd say B also

 

[jay47]

I have never heard of differences between subunits, other than those of Eukaryotes and Prokaryotes. I'd say B also

Ditto, never heard of any differences. If there are, then this is probably way to picky for DAT anyways.

 

[Sublimation]

When compared to ribosomes in free polyribosomes in the cytosol, rough ER-bound ribosomes have?

a) different large and small subunits
b) the same large and small subunits
c) different large subunits but the same small subunits.
d) different small subunits but the same large subunits.

Anyone pleae help me? I put B for this one!!! I would thanks a dozen times.......

Same here never heard of there being any difference. I would put B just off the fact that they can alternate rolls. They can go from polyribosomes to ER bound, and vice versa, so there should be no difference at all

 

[sciencegod]

would say b

 

[gentile1225]

im taking cell biology now and i would definitely agree the answer is b, but again i agree this is too detailed for the dat. i would just focus on maybe the different proteins they produce.

from wiki:
free ribsomes - Proteins that are formed from free ribosomes are used within the cell.

membrane-bound ribosomes - Bound ribosomes usually produce proteins that are used within the cell membrane or are expelled from the cell via exocytosis. Once these proteins are packaged from the er, they bud off as vesciles and fuse with the membrane of the golgi apparatus. as they pass through the golgi, from the cis face to the trans face, they are further modified and packaged along the way. once they proteins have been fully modified they are transported again as secretory vesicles to either the endosomes and then the lysosomes for cellular digestion, or to the plasma membrane and are excreted out of the cell.

Free and membrane-bound ribosomes differ only in their spatial distribution; they are identical in structure and function. Whether the ribosome exists in a free or membrane-bound state depends on the presence of a ER-targeting signal sequence on the protein being synthesized.


hope this helps. i went a little overboard on the membrane-bound ribosomes, but i just had a test on cellular transport so i know this stuff pretty well.

 

[Sublimation]

im taking cell biology now and i would definitely agree the answer is b, but again i agree this is too detailed for the dat. i would just focus on maybe the different proteins they produce.

from wiki:
free ribsomes - Proteins that are formed from free ribosomes are used within the cell.

membrane-bound ribosomes - Bound ribosomes usually produce proteins that are used within the cell membrane or are expelled from the cell via exocytosis. Once these proteins are packaged from the er, they bud off as vesciles and fuse with the membrane of the golgi apparatus. as they pass through the golgi, from the cis face to the trans face, they are further modified and packaged along the way. once they proteins have been fully modified they are transported again as secretory vesicles to either the endosomes and then the lysosomes for cellular digestion, or to the plasma membrane and are excreted out of the cell.

Free and membrane-bound ribosomes differ only in their spatial distribution; they are identical in structure and function. Whether the ribosome exists in a free or membrane-bound state depends on the presence of a ER-targeting signal sequence on the protein being synthesized.


hope this helps. i went a little overboard on the membrane-bound ribosomes, but i just had a test on cellular transport so i know this stuff pretty well.

Hey im debating on whether to take cell bio or micro bio? Since you are currently taking cell bio. Which one do you think will be better prep for the DAT. I kno most of bioI cold. Its the biological diversity that is klling me. I had to take the course in the middle of a family crises so i learned absolutely nothing. I plan on reading my Bio book for that portio of the DAT. Thanks.

 

[IWantSmile]

When compared to ribosomes in free polyribosomes in the cytosol, rough ER-bound ribosomes have?

a) different large and small subunits
b) the same large and small subunits
c) different large subunits but the same small subunits.
d) different small subunits but the same large subunits.

Anyone pleae help me? I put B for this one!!! I would thanks a dozen times.......

I think it is "C" when it is free ribosome because large (2 types of rRNA, 28s and 5s) and small (only a single 18s RNA) subunit fit together..... Maybe I should go back review.