and great number of corrections. I would also like to thank all the members of the "Lendület" Chemical Biology Research Group for their continuous help in practical matters. Furthermore I would like to thank my parents for their support. Special thanks is due to Kim Eunha and Krisztina Hegyi for the live cell imaging experiments, to Mihály Kállay for the computational data, to Szabolcs Béni for his assistance with the NMR experiments, Soma Vesztergom for the valuable discussions concerning kinetic measurements, and to the Szostak lab for the use of the stop flow system.