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bobomarleyo
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#21
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#21
Is the reason for the denaturation about pH or about how copper is heavy or about R groups?so many different answers!!

And cud ne1 help with a suitable range?

Cheerz
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Unregistered
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#22
Report 16 years ago
#22
Copper sulphate has a neutral PH, so that is not whay it ahs an effect.

PH would have a similar effect to the copper sulphate as the H+ ions in the acid would behave much like the Cu2+ ions in copper sulpate solution, by affecting the ionic bonding among R groups.

Copper being heavy is totally irrelevant.
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Unregistered
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#23
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#23
thankyou so much for all your help with this but i am unsure what method i can use to measure how opaque the egg albumen goes. does anyone have any clues?
if you can then email me at [email protected] thanx guys, bec xxx
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Unregistered
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#24
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#24
you can use a colourimeter which gives u a mesurement of opacity
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Unregistered
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#25
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#25
What if you havn't got access to a colourometer? I've heard you can use a cross on filter paper like experiments we used to do in year 7!!! but how can you then measure how far the cross has disappeared because you can't just say either it has or it hasn't!!
Thanks for all the help
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Ems
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#26
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#26
definatly use a colourimeter...
in all honesty its by far the best method and the exam board will be expecting it

most places have one colourimeter, ive used one at school. i think it is included in the list of apparatus found in a school. so dotn worry if ure school doesnt have one....
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Ems
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#27
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#27
Originally posted by Unregistered
Egg Albumen is a globular protein held together in the usual manner by interaction between R groups.

Some of the bonds between R groups are Ionic, ie a positively charged R group is attracted to a negatively charged R group and the force of attraction holds the shape of the protein.

CuSo4 disociates into Ions in solution. These Ions are also attracted to the charged R groups. the positive Cu ions are attracted to negative R groups, the Sulphate ions to the positive R groups. They effectively neutralise the charge on the R groups so that the R groups no longer bind to each other. This allows the protein to uncoil into long strands.

Some of the bonds in the portein strand are polar, slightly charged at one end.

H groups are slightly positive, and become attracted to the slightly negative O end of OH groups. As the protein has uncoiled the H and OH groups are free to line up. The resulting hydrogen bonds cause the molecules to stick together. It is this more compact regular arrangement of molecules that blocks the light and turns the albumen white.

Hope that's of some help. Mine has to be in tommorrow.
PLEASE PLEASE PLEASE can i have a reference.......!!!!
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Unregistered
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#28
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#28
Guys you dont actually need to do this experiment, its just a plan for a theoretical one. so put in lots of different methods and pros and cons for more marks


it doesnt matter if your school doesnt have a colourimeter, if you read the paper it says use anything you would expect to find in a school or collage.


alex
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Unregistered
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#29
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#29
Thanx this has been great help, pH has nothing to do with it because no H+ ions or OH- ions are released, the ions released by the copper sulphate have the same effect on the protein as a change in pH would though. good luck
Kat
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Unregistered
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#30
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#30
how many methods are there??? plz give me ideas i can only think of one method to use how to do the exp. or doyou mean how to collect results? either way i thought we only had to give one detailed method.
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Unregistered
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#31
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#31
hey im doing the egg albumen cw and i know exactly how im going to conduct my expreiment but everyone keeps giving different answer about how the egg alubmen is actully denatuerd...i know i NEED to put this in my intro but i dont know how to explain it, and if any one can help i also need a reference becasue i dont think a message board would go down too well. i need to know how the Cu2+ reacts with the COO- group, so any help i soooo welcome. and we've been told that we only have to do the preliminary test if we're not sure if our test would work or not, if this is the case how do i make an accurate prediction, and if i do do one do i need to add my results beacuse surely this is just a planning exercise not an evalution.
which brings me onto the conclusion.....what do we write in it? do we have to do the whole ..."if i repeated this study i would change this... " because we dont actully carry out the study so how can we draw up a results table and graph if we have no results. oh and if anyone knows what a colourimeter measures in then plz let me know. thank u.
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kirstie
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#32
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#32
we got ours yesterday and none of us have a clue!!!!
so any help at all would be apprieiated
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unregistered
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#33
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#33
some one please help us!! we only got r coursework yesterday, and none of us know what we r meant to be doing.
any help would be appreciated.

thanx
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Unregistered
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#34
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#34
Most of what I wrote above comes from the Cambridge advanced science Biology 1 Textbook (I think, don't have it on me, so I'm just recalling), and Salters Advanced Chemistry Chemical Ideas.

I've also referenced the UK Learning Forum. It doesn't sound too bad as a reference I think.

It's mostly deduction. Copper sulphate consists of Ions. R groups bind to each other using Ionic attraction, which adding Ions will neutralise. It's then logic that the molecule will uncoil and bind to other protein mollecules in much the same way cellulose does when the H and OH groups on the main chain of the protein line up.

There are no dedicated sources on this that I have found, so the next best thing is to use what you do know and put two and two together.
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Unregistered
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#35
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#35
Hi Im in need of serious help. Please can anyone please just give me a clue as to where to start with this coursework or some useful websites. Thanx.
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kirstie
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#36
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#36
some1 plz help me! i have not got a clue wot i'm doing would sum 1 plz send me sum info, that would really help or if i could just get an idea of wot i'm supposed to do
thanx
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angelpastry
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#37
Report 16 years ago
#37
okay, im new so be nice. i am so confused about all of this. there doesnt seem to be any good information on the net and its just really hard.

i have been told to use a colourimeter (spelling?), that box type thing that shines light through and lets you know how much light is going through. it should help with telling how denatured the egg and copper (2) suphate solution is.

the concentrations i am going to use are 0.0 (pure water), 0.02, 0.04, 0.06, 0.08 and 0.1m. they seem the simplest to be able to work out for me although im not sure if all of this matters because i dont think that the experiment actually has to be done.

Lisa-x-
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J.C
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#38
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#38
Once again, I wish to thank all who contributed to initial plee for help. My coursework has now been completed and is due for handing in tomorrow.....so wish me luck.

In conclusion, I wish to summarise what I put in mine in the hope of helping other people. Please understand that I by no means claim to say this is correct. It may well be completely wrong, so if you use this theory and it is wrong, on your own head be it. Thats my terms and conditions.......lol.

Ok....use a colourimeter.....or simply use the stronger concentrations as an easy comparision to the others. The choice is yours.

My explanation for the denaturation is a direct quote from my coursework so if you use it....PLEASE DO NOT SIMPLY COPY AND PASTE!

'Copper ions in copper (II) sulphate are highly electropositive. Within proteins exist ionic bonds, which form between polarised R groups. Because of the positive charge of the Cu2+ ions the copper ion then forms an ionic bond with the polarised R group, which is stronger than the already existing bond. As a result, the existing bonds are broken and the protein changes shape. This change in shape is responsible for the denaturation.'

A lot of this is simply repatition.

Hope that is of ANY help to anyone.....if you still have major problems....please dont hesitate to email me

[email protected]

Good luck all.....

J
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Unregistered
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#39
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#39
hey, hope everyone got their plans in on time. I've been given two weeks from now to do mine.
sounds like loads of people have done different things. i've gotta few questions that need answerin...
does diluting the copper sulphate alter the ph?
how much albumen and copper sulphate do you recommend using?
what concentrations of copper sulphate did you use?
what part of the experiment involves a change of ph if all you're doing is changing the concentration?

If you can help please email me at [email protected]
please help!!!!!
xx
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Unregistered
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#40
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#40
a colorimeter is a bit of equipment that you use to test the absorbance and transmission of the centrifuged samples from your experiments. hope this helps.xx
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