How do the macro minerals present in soil help plants ?

Macro-nutrients are nutrients required in relatively large quantities for growth and development of plants. They are six in number. Since they are required in large quantities, they are known as macro-nutrient. The six macro-nutrients required by plants are nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur.

Few roles of those elements are:
Nitrogen helps in the formation of amino acids.
Phosphorus is involved in photosynthesis, respiration, root formation etc.
Potassium is involved in carbohydrate metabolism, calcium is involved in nitrogen metabolism.
Manganese and Zinc help in chlorophyll formation.