How many peptide chains are present in $Hb$ (Hemoglobin)?

In haemoglobin,iron is attached to the globin protein by:

$A$ bond formed between the $C$-terminal of one amino acid and the $N$-terminal of another amino acid is known as:

Which of the following is $NOT$ made of monosaccharides?

Polypeptide chains present in insulin are linked together by...

In the structure of a protein,which groups are responsible for the $N$-terminal and $C$-terminal,respectively?