$A$ quaternary protein consisting of two $\alpha$-chains and two $\beta$-chains is:

Which amino acid contains a non-polar $R$ group?

Which conjugated protein is synthesized by copper?

What is the smallest structural unit (monomer) of a protein called?

In which solvent are proteins soluble?

$S$ - Statement: Proteins are called conjugated proteins when they are associated with substances other than amino acids.
$R$ - Reason: Chlorophyll is essential for photosynthesis.