Question

4. The reagents listed below are all expected to affect protein tertiary structure. or each give a brief explanation (not more than two sentences) of how they affect protein structure. (a) Urea (b) SDS (e) High temperature (d) B-mercaptoethanol (e) Distilled water ( Organic solvents adto Lranoinaoni ievn pe t wolloboie d uode bai sson eod eenlo DMA00.01 1 0d097 oup 1200W.A0L

Answer 1

4.(a) urea destabilise the internal non-covalent bonds of the protein thereby weakening its tertiary structure and thus gets denatured.

(b) SDS binds to the protein chain with its hydrocarbon tail facing towards the buried regions and it coats the protein chain with surfactants.

(c) At high temperatures the hydrogen bond and other non-polar hydrophobic bonds present between the protein molecules gets disrupted. Thus it gets denatured.

(d) Beta-mercaptoethanol denatures the protein molecules by cleaving the disulfide bonds present between them.

(e) Distilled water as such won’t affect the tertiary structure of protein but the heating of protein with water can denature it as the hydrogen bonds present gets cleaved

(f) organic solvents also disrupts the hydrophobic interactions between the non polar side chains of proteins.