Question

why does milk changes into curd

Answer 1

it due to bacteria lactbacilous

Answer 2

milk is converted into curd or yoghurt by the process of fermentation milk consists of globular protein called casein the curd forms because of the chemical reaction between lactic acid bacteria and KCL casein during fermentation the bacteria used enzymes to produce energy ATP from lactose. the byproduct of ATP production is lactic acid lactic acid and on the globular protein present in the lactic acid acts on the Globalular proteins present in them. and thus we get curd