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Unregistered
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#1
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#1
i am doing a biology AS level investigation the lowest concentration of copper sulphate that will denature egg albumin and i need to know how i tell when all the egg albumin has been denatured! can some1 help me im stuck and no books have this in!
thanks
bec
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Susanna
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theres quite a few threads that already have the answer to that, if you look through you should be able to find them
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nashb
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well.... albumin is protein isnt it... so do the protein test:

Biuret test - for Proteins
- Add Biuret solution (sodium hydroxide + small amount of copper sulphate) - blue, like Benedict's - to the test substance.
- THERE IS NO NEED TO HEAT, but the result is not quite instantaneous.
A colour change: blue to mauve shows the presence of a protein.

isnt so hard is it.. put ur brain into it!
hope u found this helpful!
take care.x
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Unregistered
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when the solution turns opaque, it has fully denatured. e.g. when u fry n egg the white turns WHITE
simple tings
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Ems
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#5
Originally posted by nashb
well.... albumin is protein isnt it... so do the protein test:

Biuret test - for Proteins
- Add Biuret solution (sodium hydroxide + small amount of copper sulphate) - blue, like Benedict's - to the test substance.
- THERE IS NO NEED TO HEAT, but the result is not quite instantaneous.
A colour change: blue to mauve shows the presence of a protein.

isnt so hard is it.. put ur brain into it!
hope u found this helpful!
take care.x
this doesnt actually help with the denature part...

it says in the thing u get that egg albumin goes opaque when denatured....

so just meassure the opaquity of the egg or "HOW MUCH LIGHT GOES THRU" ie use a colourimeter...
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Unregistered
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i also gotta do a pract exam on CUSO4 and egg white....
i dont have a clue what is going on so does anyone know where i can get some infromation from?

cheers
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Unregistered
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hi, yea just finished my coursework, its a right *****, anyway think about it this, way, when you add 0.1M dm of CuSO4, the egg turns completely opaque and goes kind of a whitish blue, so as you decrease the concentration of CuSO4, if the egg is fully denatured, you should get a similar result, by the way, the lowest conc is between 0.001M and 0.01, im not exactly sure though, but theres a rough idea, hope it helps
alex
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Unregistered
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Im doing it too!!! EEK!
does it have something to do with the disulphate bonds in the proteins? and also something to do with the 'Heaveyness' of the metal (Cu)?
Its soo hard!
any more info from anyone would be EXTREMLEY useful!
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Unregistered
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Originally posted by Unregistered
i am doing a biology AS level investigation the lowest concentration of copper sulphate that will denature egg albumin and i need to know how i tell when all the egg albumin has been denatured! can some1 help me im stuck and no books have this in!
thanks
bec
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GAv
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You need to go through all of this for a simple AS planning paper.
Hahaha.

(moderator: snip. Don't be nasty )
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Unregistered
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#11
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#11
Originally posted by Susanna
theres quite a few threads that already have the answer to that, if you look through you should be able to find them
the problem with this is when you add biuret reagent a purple colour appears and the less protiens the less the colour

simple

but you forgat that the solution is also going cloudy at the same time so useing a colourometer would become pointless!!!!!!!
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Unregistered
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When egg albumin denatures it goes opaque when it is fully denatured no light can pass through it. There is a piece of equipment called a colorimeter that measures how much light can pass through the albumin when it shows that there is no light passing through then the egg albumin has been completely denatured. There is no need for the biuret test.
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Hello This is Dr Niel

I thought i would help you all out by telling you that the R-Group ovalbumin contained in the albumin protein conducts electricity before denbaturisation has occured, but afterwards it does not conduct at all as the bonds are no longer in the correct ionic formation to pass the current through. Therefore the most simple and accurate test would be to run electrisity throught the soloution and when it stops conducting that is the value when denaturisation occurs.

Hope that this helps, good luck on tuesday
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