ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: slothpomba on March 27, 2010, 11:37:43 pm
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What exactly is fractioning?
I'm not sure if we need to know it.
I havent came across it in my nature of biology text book yet.
I have, however, seen it in biozone and a previous exam.
So, do we need to know it/ where can i find it in biozone/ is it even in the area of study im looking at (Unit 3 AOS1)?
Thanks guys
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yeah you need to know it.
it is called cell fractionation, and it is somewhere in the biozone book.
the main principle behind it is that heavier/denser organelles, will sink to the bottom
main purpose is to get samples of individual types of organelles.
basically what happens is:
-cells put in some kind of blender, chopped up to break cell membrane, releasing all of the organelles.
-sample is then put into a test tube, and placed into a machine called a centrifuge.
-the thing then spins, applying a force to the solution. heavier organelles will fall to the bottom the easiest. (i.e. at a slow speed). once the heaviest organelles have been separated to the bottom of the test tube, forming what is called a pallet, the solution above it, the supernatant, is removed, placed in another test tube.
-the process is then repeated, at a higher speed, and the next heaviest organelles will form a pellet. Process continues until you have separated all of the organelles.
As heaviest organelles form a pellet the easiest, the order of collection is usually nuclei, mitochondria, ribosomes etc...
here is a pic which might make it clearer...
http://www.freewebs.com/ltaing/chpt7.3Cellfractionation.gif
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It was on 2009 exam 1 multi-choice :).
It gave you a lil bit of background info though, but you had to know the order of heaviest components.
I got that question wrong because I didn't understand the ordering.
BE WARNED, ALL.
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So...what is the order? :angel:
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It was on 2009 exam 1 multi-choice :).
It gave you a lil bit of background info though, but you had to know the order of heaviest components.
I got that question wrong because I didn't understand the ordering.
BE WARNED, ALL.
Shows how you can lose a few marks in Biology and STILL get a 50, whereas in methods its basically 10 marks gone and you score a high 30...
Not really. I lost like 3 marks minimum. Depends on the year really...
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Also, in Methods, I lost 10.5 and got 42...
That said, I did have first ranking, so you could drop into the thirty's with lower SAC's...
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It was on 2009 exam 1 multi-choice :).
It gave you a lil bit of background info though, but you had to know the order of heaviest components.
I got that question wrong because I didn't understand the ordering.
BE WARNED, ALL.
Shows how you can lose a few marks in Biology and STILL get a 50, whereas in methods its basically 10 marks gone and you score a high 30...
Not really. I lost like 3 marks minimum. Depends on the year really...
Yeah you lost 3 and got 49? Maybe I should write "couple" instead of "few" next time..
Sorry I meant for Methods.
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Yeah I lost like 5 marks on exam one and 7 in exam 2, hence I never expected 50 for Bio.
METHODS, on the other hand. I lost like, 13 marks on exam 2 and like 11 on exam 1 or something.
Good.