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questions on life science homework, looking for explanations - (Jan/10/2012 )

which of the following organelles that produce proteins would you expect to be especially abundant in these amylase producing cells type?
A)chloroplasts
B)rough endoplasmic reticulum
C)lysosomes


the word fluid in the term fluid mosiac model refers to the fact that
A)membranes are selectively permeable
B)the proteins within a membrane freely move around
C)the membrane assembles and disassembles as necessary for cell function


the proposed role of capsaicin in anesthesia during surgery is to
A)open channel proteins found only in pain-sensing neurons allowing an anesthetic to enter those cells alone
B)increase the rate at which calcium ions enter a nerve cell
C)block the transmission of electrical signals between nerve cells and muscle cells

Thank you very much. I can't quite grasp these concepts and the homework spans a few lessons' material I seem to be missing

-NiceWatch-

which of the following organelles that produce proteins would you expect to be especially abundant in these amylase producing cells type?
A)chloroplasts
B)rough endoplasmic reticulum
C)lysosomes


This is an easy one, all you have to do is think is one of two things: what do these things do? OR what have they just told me that the organelle needs to do? This isn't to do with concepts, this is just knowledge and you can find the answers on the Wikipedia pages. Wikipedia is actually (although it's taboo to say...) a very good source of basic information on most things scientific.
In a very simplified version, lysosomes break things down, rough endoplasmic reticulum is choc-full of ribosomes and this is what makes it look 'rough' rather than smooth, the fact that it has all these tiny bobbly ribosomes on it (and do you know what ribosomes do?), and chloroplasts are to do with energy production in plants. You should be able to see which is correct from that!

the word fluid in the term fluid mosiac model refers to the fact that
A)membranes are selectively permeable
B)the proteins within a membrane freely move around
C)the membrane assembles and disassembles as necessary for cell function


Google gives me this right away: http://www.dummies.com/how-to/content/the-fluidmosaic-model-of-the-cell-plasma-membrane.html which answers this question for you :) You can also discard C right away as sounding stupid because the cell would have no integrity if its membrane started randomly disassembling!

the proposed role of capsaicin in anesthesia during surgery is to
A)open channel proteins found only in pain-sensing neurons allowing an anesthetic to enter those cells alone
B)increase the rate at which calcium ions enter a nerve cell
C)block the transmission of electrical signals between nerve cells and muscle cells


Googling "capsaicin anaesthesia mechanism of action" gave me: http://bja.oxfordjournals.org/content/75/2/157.full.pdf which if you read the first page, you should spot where the facts are which tell you if you have the right answer.

I'm just giving you google information etc. to illustrate how, when you're stuck on homework in future but you can't find somebody to help you in time, it's actually very easy to help yourself. Indeed that is largely how you have to learn at University :P

Good luck with your work. Also if you still can't work out which answers are correct after reading those things, just say and I (or somebody else, I expect) will be able to tell you!

-seaholme-

These may be simple answers for you but this is all very new material for me. Unfortunately in South America we don't utilize much science in school unless you can afford a very high private school or something. However you are a very helpful teacher and I am thankful for your quick and strong response. Thank you. I understand the first two and is the third one (C)? The article talks about "a block of transmitter release would inhibit the transmission of noxious signals..."

-NiceWatch-

Well simple answers as in you don't have to have much understanding of concepts, just some factual knowledge, so it's quite easy to find the answers despite not having necessarily learned them before, is what I meant. There are definitely some subjects where a lack of background and conceptual understanding would greatly hinder you. I didn't mean to suggest that it wasn't new material for you.

If you read the line that goes from the last sentence of the left-hand side up to the first sentence of the right-hand side, on the first page, you would probably conclude B? It isn't answered in the first paragraph, so you have to read on a bit and get through the whole of the page.

A block of transmitter release would inhibit transmission of noxious signals, but you should also consider the whole of the statement rather than just the first part. The statement they gave you C)block the transmission of electrical signals between nerve cells and muscle cells has 2 parts to it:
1. blocks transmission of electrical signals
2. between nerve cells and muscle cells

I agree that the sentence you found fits with part 1, but does it fit with part 2? I think not. If you had a look around, you'd find that capsaicin does not transmit signals between nerve and muscle cells. If it did, there'd be some kind of muscular reflex - and if you use a bit of common sense, "capsaicin is the active ingredient in hot chili peppers" (from the article, assuming you didn't know it already) and have you ever eaten a chili and had some kind of muscular spasm?! It's just a nerve sensation when you eat a chili, so you can use common sense to cross C off the list almost from the start.

All you need are the facts and a bit of logical common sense thinking :)

-seaholme-