Which one of the following biomolecules is insoluble in water?

Identify the incorrect statement about the tertiary structure of proteins.

Which among the following is a source of wool?

The helical structure of protein is stabilized by

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ solution of the product obtained by heating a mole of glycine with a mole of chlorine in the presence of red phosphorus generates a chiral carbon atom.
Reason $R$: $A$ molecule with $2$ chiral carbons is always optically active.
In the light of the above statements,choose the correct answer from the options given below:

What is the total number of essential amino acids?