Question

Urea is a reagent that disrupts non-covalent bonds in protein molecules, but leaves covalent bonds intact.

2 questions:

Would urea reduce the molecular weight of a single polypeptide chain?

Would urea reduce the molecular weight of a protein composed on more than one polypeptide chain?

		Yes and yes.
		Yes and No
		No and No.
		No and Yes.

Answer 1

the answer was NO & YES

because,peptide bonds are covalent in nature.according to the given data the given reagent only disrupts non covalent bonds that means the peptide bond doesnot disrupted as it is covalent.

Therefore urea wouldnot reduce the molecular weight of a single polypeptide chain.

coming to the second case if a protein is composed of more polypeptide chains the interaction between the polypeptide chains is not a covalent bond it may be a intermolecular hydrogen bonding which can be disruped by the given reagent.

Hence we can say urea would reduce the molecular weight of protein if it is composed of morethan one polypeptide chain.