AS Biology Coursework

I am currently working on my biology AS planning coursework and was wondering if anyone could lend me a hand. So far, I have written everything expect for the explanation of my prediction. The aim of the investigation is to find the lowest concentration of copper (II) sulphate that will bring about the full denaturation of the proteins in egg albumen.

Im a bit stumped in the sense....I dunno how it actually does it. Could anyone that knows perhaps shed some light on the matter???

Thanks,

J

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Reply 1

Unregistered

denaturation occurs as a result of the hydrogen ions increasing the acidity of the mix which changes the primary shape of the egg albumen protein. this in turn means that the solution goes clear.
could you in turn tell me what the concentrations were that you got in the experiment? basically what denatures it and what doesnt
cheers, good luck with your work
charlie

Reply 2

Unregistered

That's not quite how it happens in this case.
What actually happens is heavy metal ions (ie copper in your case) are highly electropositive. they combine with COO- groups and disrupt ionic bonds. thus denaturing the protein.

Hope that helps i'm doing it

Reply 3

Unregistered

hello im have huge amounts of problems with this albumen coursework could u plz help.

i did the prelim experiments and i got horrible results
both albumen and copper 2 sulphate were diluted.

Reply 4

Unregistered

I am also stuck, james its me! SL Its really hard and there is nothing to help on the internet!

Reply 5

Unregistered

i have done the same coursework.... on the experiment it say that the test is to be done at room temp that rules out the temp denaturing the protien (albumen) so copper 2 sulphate changes the ph. albumen has an optiumin pH when you change the ph of its local enviroment you change the structure of protien by messing up the bonds between the R-groups of the amino acids which make up the protien this is what causes the protien solution to go from clear to opeque (cloudy)

if you want to know what should happen to the egg albumen you should watch an egg fry it has the same affect!!!

hope this helps............. kurt...............!!!

PS: mail me a draft and i will give you some pointers and that shit !!

[email protected]

Reply 6

Unregistered

ok rite this c/w is doin my head in i really got no idea where to start obviously with a intro but i jus need sum hints anyone with any good webpages or anything (im very desperate) pleez e-mail me or summut

[email protected]

it wud be really appreciated

Kris

Reply 7

Unregistered

Thx for every1's input!!
Will help for the background info.
Below is a table of prelim results if ur interested:
Egg: 5ml

cus04(ml) h20(ml) light transmission (%)
10 0 1
7.5 2.5 1
5 5 2
2.5 7.5 2
0 10 100
1 9 40
0.5 9.5 58
0.25 9.75 65

Hope this helps!!
any other info on background info plz mail me:
[email protected]

Reply 8

Unregistered

Hey all, thank you to everyone for their help, its been extremely useful! Im still a little unclear however. In my explanation, I have put that the Cu2+ ions are electropositive and that they bond in favour of the already existing ionic bonds between amino acids. However a few people have mentioned that pH would also effect it. Obviously this is the case, but is copper (II) sulphate really THAT different pH wise? And if it can denature it because of this, then would it be sumink to do with the concentration of H+ ions?????

J

SL: Hey loserette :wink:

Reply 9

Unregistered

hi i am stuck on the same biology prac as you and was just wondering if you could give me any tips

Reply 10

Unregistered

does da copper (II) sulphate change pH???

Reply 11

aysha

any enzymes involved?
does it need to be timed for fair test?
how ph change scintif kwnol?

Reply 12

Unregistered

HELP, HELP, HELP. Everybody seems to be stuck on this coursework. The problem is I really don't have a clue because we were given the coursework and then had to do it over Easter with no help what so eva. Thanks for all the info but IM STILL STUCK!!!
Could someone just reply with some really simple starter stuff so I can understand it even just a bit!!

Thanks

If theres anything really useful e-mail me on:

[email protected]

Reply 13

Unregistered

How do you actually change the concentration of copper sulphate? Anyone know the formula?

Reply 14

Unregistered

Albumen is a protein which has a tertiary structure partly casused by ionic bonds btwn NH2- group and COO-. The Cu2+ ion reacts with the COO-, breaking the bond denaturing the protein.

To get different concentrations of copper sulphate dilute it with water and have different ratios.

Hope that helps

Reply 15

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.

Reply 16

Unregistered

Hey,
I had no idea so many people were fnding this as hard as I was, everyone in my class said twas really easy.

Anybody have a good control experiment?

I'm unsure whether to try a different sulphate, e.g. FeSO4 to show its only copper sulpahte that will do it or prove that the egg albumen has been denatured.

Any help with this would be extrememly well received.

[email protected]

Thanx

Reply 17

Ems

i wouldnt bother bout the diff sulphate cus it tells you its denatured you just gotta explain why/how and say the lowest conc. it occurs at...

in my preliminary i found that between 0.1mol and 0.05 its completly denatured so theres no point using those conc. and by saying this u get marks according to the mark guide we got with AQA!

generally just go for a good method and explanations on why you do what youre doing cus it looks like thats what they want from the mark guide.

good luck!

Reply 18

Unregistered

Cheers Ems, that was really helpful. My perliminary work was pretty disastrous cuz we kept halfing the concentration each time.

Anyways best get back to it, it's due in tomoz.

Fran
XXX

Reply 19

Unregistered

so which methods hav been used?

I measured the weight of the co-aggulate once centrifuging the egg albumen and the copper (II) sulphate. Once all of the protein had been denatured I found what the mass of complete denaturation was. Then by reducing the concentration of copper (II) sulphate solution I found what the concentration needs to be so that the copper (II) solution gives the same mass as the highest concentration. That way I ensured that I ended up with the same mass of co-aggulate as complete denaturation.

I dont think that this is the best method though. Anyone with any better methods?

cheers,

peace...