Question

Why are proteins water soluble and why do they become not water soluble after denaturation?

Answer 1

Hint: Proteins are water soluble in nature. They have great importance in our day-to-day life. They have been built up from amino acids. They are large biomolecules that are composed of one or more long chains of amino acid residues. A protein contains at least one long polypeptide (a linear chain of amino acid residues) chain.

Complete answer:
After denaturation of proteins they become not water soluble. The reason behind that is that when a solution of protein is boiled, the protein frequently becomes insoluble and remains insoluble even when the solution is cooled. After denaturation, no change occurs in the structure of protein means the denatured protein and native protein have the same primary structure. With the help of alkaline or acid, oxidizing or reducing agents, and certain organic solvents, proteins get denatured. As we know that they have been built up from amino acids so in amino acids the side chains have different properties, some of them are hydrophobic in nature while some of them are hydrophilic in nature. After the denaturation is done, it changes the $3D$ shape of proteins and gets unfolded. In this way some hydrophobic side chains which are buried inside the protein are exposed thus making the protein insoluble in nature.

Note:
Protein is a macronutrient which is essential for building muscle mass. It is mainly found in animal products, but also in other sources like nuts and legumes. There are three macronutrients available which are protein, fats, and carbohydrates. They all provide calories, or energy to our body to meet our daily requirements in our day-to-day life.