Revisiting the microtubule based quantum models of mind: tubulin bound GTP cannot pump microtubule coherence or provide energy for alpha <-> beta computation in stable microtubules

The current paper investigates the biological models of stable brain microtubules as quantum or classical computers whose function is based on electron hopping associated with kinking of the tubulin dimer. Hameroff (1998a, 1998b, 2003a, 2003b), Tuszynski et al. (1998), Hagan et al. (2000), Mershin et al. (1999); Mershin (2003) suppose that the energy needed could be somehow delivered via guanosine diphosphate (GDP) exchange for guanosine triphosphate (GTP) or via cycles of tubulin bound GTP hydrolysis. Here is presented biological and structural data from electron diffraction studies performed by Lowe et al. (2001) and computer simulation with MDL ® Chime Version 2.6 SP4, explaining and visualizing the inconsistency of the proposed tubulin bit (qubit) GTP energized alpha <-> beta computation and/or tubulin bound GTP pumped coherence in stable microtubules.