The helical structure of proteins is stabilised by
peptide bonds
dipeptide bond
hydrogen bond
van der Waal's forces
Lactose sugar is formed from
d-galactose
d-glucose
d-galactose and d-glucose
d-glucose and d-fructose
Vitamin-B12 contains
CO
Fe
Zn
Ca
A.
CO
Vitamin - B12 or cyanocobalamine consists of cobalt.