Question

Urea is commonly used in laboratories. What will be the effect of adding a concentrated urea solution to a protein?

denaturation of protein

no effect

change in the sequence of amino acids

Answer 1

@tkriz972 Well since urea is also known as Uric acid, and since its an acid it will most likely affect the ph of a protein, in turn will _________?

Answer 2

i dont understand

Answer 3

@tkriz972 Since it affects the ph of a protein, it will make it not stable and will cause it to denature.

Since proteins are certain temperatures will denature, if the protein is stable and then uric acid is added, the ph will change the temperature of the protein, and hence will cause it to unfold and denature.

Answer 4

thank u

Answer 5

Make sure you medal if you received the correct help :)

Answer 6

i dont know how

Answer 7

nvm

Answer 8

It will denature it. You'd end up with a soluble unfolded protein.

Answer 9

@alphadxg While your answer is correct that urea tends to destabilize proteins your explained mechanism is incorrect, also you are mistaking urea and uric acid.

Urea is not an acid but rather a base as it is a carbamide, while uric acid is a heterocyclic molecule. The most general accepted mechanism of urea denaturation is urea is hydrogen bonding to polar residues in the protein (e.g. peptide groups for secondary structure) thereby screening for internal intermolecular hydrogen bonding.

Another mechanism is urea promote protein folding by altering water's structure and dynamics which contribute to diminish the hydrophobic effect facilitating water exposure of the hydrophobic core residues.

Answer 10

@Frostbite I don't think the mechanism has much meaning to this, its a general concept. Even If i mistaken the mechanism, the understand should be the same.

Answer 11

@alphadxg It may be the mechanism has nothing to do with this, but then again I wanted to avoid that tkriz972 gets the idea that the denaturnation occurred as an effect of pH changes from urea as you point it out.

Another thing is you choose to say urea = uric acid which is very much incorrect. They are different molecules and occurs in different pathways (attachment shows the production urea from L-arg and the production of uric acid from AMP and GMP).

I am saying this to avoid confusion as you seem to otherwise state.

Answer 12

Again, the understanding is there, it was an example.