Question

Can someone explain why/how lactase breaks down lactose but using the concept of Induced fit and Active sites

Answer 1

Induced fit hypothesis is used to explain mechanism of action of lactase and in general for other digestive enzymes.The part of the enzyme lactase, which binds to the substrate to transform it into product is called the active site. When lactose(substrate) binds to lactase, the binding causes conformational changes in lactose(substrate) and active site of lactase(enzyme) .These conformational changes induced by lactose  enables precise orientation of lactase which is required for its catalytic activity and is termed as induced fit . With the precise orientation, lactase now acts by weakening the bonds in lactose to convert them into glucose and galactose.