How a particular composition of molecules result into life in form of cell?
Science does not have an answer to how the first reproducing cell came about.  The actual event has left no traces except life as we see it today. There are theories about parts of how it might have happened, but evidence about it essentially doesn't exist.  If you want to get a flavor of recent ideas of scientists in this area, here is a video of a lecture on "The Origin of Cellular Life on Earth".