smooth ER - membrane synthesis

[dat_student]

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TopScore's test #2 question #5
TopScore says smooth ER is involved in phopholipid synthesis, lipid & steriod synthesis but not in membrane synthesis. Isn't membrane composed of lipids? smooth ER also seems to play an important role in membrane synthesis. TopScore says membrane synthesis is the job of rough ER !!!! As far as I can remember in membranes we have more lipids (smooth ER) than proteins (rough ER). Any ideas?

 

[jinnymusic2000]

I asked my bio prof. the same question you posted.
He said, smooth ER do membrane synthesis but do not sexhormone synthesis.
so, the answer of that question is sexhormone synthesis.
basically, topscore answer was wrong.

 

[dat_student]

I asked my bio prof. the same question you posted.
He said, smooth ER do membrane synthesis but do not sexhormone synthesis.
so, the answer of that question is sexhormone synthesis.
basically, topscore answer was wrong.

sex hormones are steriods. Sex hormones have to be synthesized in a cell. They don't get synthesized in an extracelluar environment. In fact, phospholipids, fats & steroids are synthesized in the smooth ER. So, it seems to me that smooth ER is also involved in sex hormone synthesis.

 

[johnwoo19]

steroids are just modified lipids so I would think that smooth ER is involved in sex hormone synthesis.....

yea that question on Topscore confused the heck outta me.....no idea what the answer is tho, I would think smooth ER is involved in membrane (phospholipid) synthesis

 

[dat_student]

steroids are just modified lipids so I would think that smooth ER is involved in sex hormone synthesis.....

yea that question on Topscore confused the heck outta me.....no idea what the answer is tho, I would think smooth ER is involved in membrane (phospholipid) synthesis

I believe the smooth ER is involved in all 5 and therefore the question has no correct answer. A lot of students have reported that they have done much better on the real test. Could it be because all practice tests have so many mistakes and therefore students cannot possibly get accurate predictions????? I have reported 20-30 mistakes to "ace the dat" and I am sure they have many more mistakes. I gave up reporting their mistakes because their science tests seem to have been written by people who failed miserably in school. I have reported many mistakes to "KSF" (ACA & PAT) and gave up reporting after I found their PAT is in a horrible shape. They claim to have corrected their mistakes in the 2nd version but they don't want to let me have the 2nd version eventhough I paid for their tests!!!! I have reported around 30 mistakes to Kaplan. I have found at least 5 mistakes on TopScore tests & TopScore has very effectively blocked its "request forms" to avoid paying $10 / mistake !!!!!

 

[kew]

The way I justified this answer is by agreeing with the problem. I figured lipid are made in the smooth ER like it said and that membrane synthesis is in the rough ER. I decided to interpret membrane synthesis as protein synthesis. I thought about the mosaic model of membranes and how there's tons of proteins in the membrane and these proteins are made in the rough ER. And again the actual lipid portion of the membrane in the smooth ER.

 

[dat_student]

The way I justified this answer is by agreeing with the problem. I figured lipid are made in the smooth ER like it said and that membrane synthesis is in the rough ER. I decided to interpret membrane synthesis as protein synthesis. I thought about the mosaic model of membranes and how there's tons of proteins in the membrane and these proteins are made in the rough ER. And again the actual lipid portion of the membrane in the smooth ER.

no way ! Do you mean the phospholipid membrane has more proteins than lipids???? That is NOT what the moasic model says... Do we have (1) a phopholipid bilayer with some cholestrol to stabilize the fluidity & some embedded proteins OR (2) 99% protein polymers with a few scattered lipids & cholestrol molecules ???!!! [the latter makes no sense] Your argument makes no sense to me and seems to go against the known structure of membranes !!!

 

[mochafreak]

I believe the smooth ER is involved in all 5 and therefore the question has no correct answer. A lot of students have reported that they have done much better on the real test. Could it be because all practice tests have so many mistakes and therefore students cannot possibly get accurate predictions????? I have reported 20-30 mistakes to "ace the dat" and I am sure they have many more mistakes. I gave up reporting their mistakes because their science tests seem to have been written by people who failed miserably in school. I have reported many mistakes to "KSF" (ACA & PAT) and gave up reporting after I found their PAT is in a horrible shape. They claim to have corrected their mistakes in the 2nd version but they don't want to let me have the 2nd version eventhough I paid for their tests!!!! I have reported around 30 mistakes to Kaplan. I have found at least 5 mistakes on TopScore tests & TopScore has very effectively blocked its "request forms" to avoid paying $10 / mistake !!!!!

I think I'm going to create a thread that points out the errors found in our study guides and especially the practice tests. It's disgusting paying so much money for this stuff and then the companies won't even report the errata. I haven't started practice tests yet, so I won't be contributing much intially. I've been doing Examkrackers problems and fortunately they have forums for each of their books that cover questions about problems, errors, etc. Too bad the others don't care enough to offer that feature. 😡

 

[tweety0805]

The way I justified this answer is by agreeing with the problem. I figured lipid are made in the smooth ER like it said and that membrane synthesis is in the rough ER. I decided to interpret membrane synthesis as protein synthesis. I thought about the mosaic model of membranes and how there's tons of proteins in the membrane and these proteins are made in the rough ER. And again the actual lipid portion of the membrane in the smooth ER.

I agree. I noticed that whenever there is a problem like this, above is what they want you to know.

 

[dat_student]

I agree. I noticed that whenever there is a problem like this, above is what they want you to know.

kew seems to be mad at me and is bombarding me with private messages. Is there a way to block kew from sending private messages? .....I don't like to argue with a salesperson. kew is attacking my character instead of telling me why he/she thinks we have more proteins in the phospholipid bilayer membrane.....

 

[puncho]

go under his name and click the view public profile. Then on the right hand side, you should see the ignore feature. Click that and I think it'll ignore him both on the forum and w/ pms.

 

[ddsnp]

I think these tests were put together by uneducated animals. I have the book they cite in every question. And I think it comes down to what the answers say. One of them says Membranes Synthesis and the rough er makes its own phospholipids so it can grow. I think its a stupid question.

 

[dat_student]

I think these tests were put together by uneducated animals. I have the book they cite in every question. And I think it comes down to what the answers say. One of them says Membranes Synthesis and the rough er makes its own phospholipids so it can grow. I think its a stupid question.

watch out ! kew may come after you via PMs...Like I said, I really don't know what sources some of these test writers use...I give you guys another example without naming the company: xxxx company claims that light acts as an enzyme in photosynthesis...lol

 

[ddsnp]

hey i also have another question....topscore says that an action potential can be generated when the outside reaches a threshold value..but isn't the threshold value the difference in concentrations between the outside and inside...? thanks


kew can harass me all he/she wants.

 

[dat_student]

hey i also have another question....topscore says that an action potential can be generated when the outside reaches a threshold value..but isn't the threshold value the difference in concentrations between the outside and inside...? thanks


kew can harass me all he/she wants.

voltage is relative. So an action potential can be generated when the diff. passes a threshold.
The voltage of outside compared to itself is zero. The voltage of inside compared to itself is also zero.