Miller urey experiment

They created probable conditions of primitive earth in the laboratory. They used spark discharge apparatus that had two tungsten electrodes to provide electric discharge (simulating lightning of primitive atmosphere). An atmosphere of gases (CH4, NH3, H2O, H2) was created in a chamber and condensed liquid allowed to accumulate in another chamber. Energy supplied by heating water in another chamber. After some days amino acids like glycine, alanine and some more complex organic compounds were collected in vitro like  purine, pyrimidine, sugar,glycerol, formic acid,short chain etc. This indicated the possibility of origin of life from inanimate matter on the earth, when atmosphere was reducing (containing no free oxygen), containing gases like methane, ammonia, hydrogen sulphide, frequent lightning and enough water was present. Simple amino acids which are building blocks of proteins might have given rise to complex molecules that are building blocks of cells.