Zinc is used in the synthesis of a type of auxin, IAA (indole-3-acetic acid). Sulphur is present in two amino acids - cysteine and methionine and is the main constituent of several coenzymes, vitamins (thiamine, biotin, Coenzyme A) and ferredoxin. Magnesium is a constituent of ring structure called chlorophyll and helps to maintain the structure of ribosome. Molybdenum is a component of several enzymes like nitrate reductase and nitrogenase which takes part in the nitrogen metabolism.