title: Analog-digital molecular cell computer.
abstract: The living cell is controlled by a molecular stochastic computer of parallel-successive action. MCC may be equivalent to the universal computer. MCC operates with molecule-words (DNA, RNA, proteins) according to the programme recorded in DNA and RNA. Operations are produced by molecular devices (RNA- and DNA-polymerases, ligases, proteinases and so on). Molecular devices operating with molecule-words are recorded on molecules themselves, and they are read off by ribosomes. Therefore the programme of the reorganization of the programme itself may be recorded on the molecule-words. MCC operates with molecular words having definite addresses. The words and the operators collide by Brownian movement and combine if the molecular surface of address segment is complementary and properly oriented. It is possible to reproduce not only the programmes but also the operators of MCC. The molecular computer operates with word-molecules according to the programme, recorded in DNA, with the aim of predicting an outer situation in the next time-moment and selecting of a correct answer by synthesis of suitable proteins and other substances and also by macroscopic motion. Each step of directed calculation is needed of the consumption of minimally necessary portion of free energy and search is due to the Brownian movement without free energy loss. Cyclic nucleotides are intraneuron membrane potential controlling systems which can be described as molecular diffusional analog computers, well fitted to solve mathematical physics equations if there are high frequency generators and regulators of cyclic nucleotides sources and sinks. It is suggested that molecular proton channels in an electric field are such generators of 10(11)-10(12) Hz. Biophysics cannot use the ordinary laws of physics and must take into account the influence on the phenomena to be studied, not only of a measurement but also of a calculation process in the real device predicting the future.
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D001921:Brain / Q000502:physiology*; D002468:Cell Physiological Phenomena; D003201:Computers; D004247:DNA / Q000378:metabolism; D009474:Neurons / Q000502:physiology*; D009712:Nucleotides, Cyclic / Q000378:metabolism; D011336:Probability; D011506:Proteins / Q000378:metabolism; D012313:RNA / Q000378:metabolism
chemical_list: D009712:Nucleotides, Cyclic; D011506:Proteins; D012313:RNA; D004247:DNA