What is formed by the combination of one or more polypeptide chains?

Schematically represent primary, secondary and tertiary structures of a hypothetical polymer, for example, a protein.

Which bonds are present in the formation of quaternary protein structure?

Which conjugated protein is synthesized by copper?

Which of the following are basic amino acids?

$S$ - Statement: The amino acid with a non-polar $R$ group is serine.
$R$ - Reason: The amino acid with a polar and uncharged $R$ group is threonine.