The concepts developed previously on the Fourier-transform analysis of the interaction potential between an atom and a discrete matter helix and on the rules governing the confinement inside the helicoidal cavity are applied to the adsorption of various gas molecules (rare gas, N-2, O-2, CH4) in a cylindrical pore of AlPO4-5. The stable adsorption sites and the equilibrium valley along the cavity are determined. The isosteric heat in the low coverage limit and the Henry constant are then calculated and trends for molecular mobility and formation of low dimensional ordered molecular structures in the pore are discussed and compared to available experimental information.