The micronutrients or the minor elements are the ones which are not required in large quantities. The minerals required can be either macronutrients or micronutrients. Macronutrients are the elements which are required in large amounts like carbohydrates, proteins, fats whereas micronutrients are those which mainly act as a co-factor of enzymes. Eg: Copper acts as a co-factor of the enzyme cytochrome oxidase, iron is needed by the enzyme catalase etc.