Do cells always have to be developed from organic carbon-containing compounds?
Twenty round openings, each surrounded by an alternating series of nine molybdenum and nine oxygen atoms, form pores in the artificial cell membrane. Covalently bound in the interior are twofold negatively charged sulfate groups, which provide for a significant negative charge on the surface of the capsules. Water molecules are also found inside the sphere. Each pore is closed off by a stopper consisting of a urea molecule bound to the Mo9O9 ring by noncovalent interactions. A typical example of biological signaling processes in living cells is a controlled ion flow through special channel proteins in the cell membrane. This can be controlled through the binding of a suitable ligand or by the electrochemical potential across the cell membrane, so ultimately by the difference in concentration of ions inside and outside the cell. Calcium ions (Ca2+) play an important role in many biological functions. For this reason, Mller et al. chose to use Ca2+ for their further experiments. They add
