BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Because urea can disrupt quaternary structure, it can conver a native multi-subunit protein to its constituent subunits (as long as there are no disulfide bonds holding the subuints together). The subunit will have lower MWs than the the intact native protein.

Detailed explanation-2: -The urea agent is used to break down non-covalent bonds such as hydrogen bonds holding the secondary structure while the beta-mercaptoethanol was used to reduce and break down the disulfide bonds holding the tertiary structure together.

Detailed explanation-3: -Urea is commonly used to denature proteins and to induce conformational changes in their tertiary and secondary structure.

Detailed explanation-4: -The primary structure is held together by covalent peptide bonds. They are formed during the process of protein biosynthesis, where the amino acids lose one water molecule per reaction to attach to another amino acid. The secondary structure is determined by hydrogen bonds between the main-chain peptide groups.