Answer to Question #131188 in Physical Chemistry for Tenzin

Question

Set the correspondence between the conditions of the process and its result:

Conditions of the process:

1) heating the protein

2) the interaction of the protein with concentrated nitric acid

3) the effect on the copper sulfate protein in the presence of alkali

4) the effect on the lead sulfide protein

Result:

a) protein denaturation b) black staining

c) yellow staining d) purple staining

Answer 1

• Heating the protein causes its denaturation.
• Proteins react with nitric acid forming yellow products.
• Copper sulfate with alkali causes the formation of purple complexes with proteins (Biuret reaction).
• Lead sulfide test is characterized by formation of black PbS precipitate.

Therefore, the correspondence is:

1 - a

2 - c

3 - d

4 - b