The Enclosure of Biologically Relevant Molecules Within a Membrane-Bound Protocell

Multiple Choice

The enclosure of biologically relevant molecules within a membrane-bound protocell could have facilitated the evolution of metabolism and self-replication, which are hallmark properties of living cells.However, enclosure by a membrane would also create a challenge to the emerging cells, in that they would need some method to evolve that allowed nutrients and building-block molecules to pass from the environment into the protocell interior.Otherwise, the protocells would be doomed to die without this influx of matter.To explore this idea more, how could a scientist best design an experiment to investigate the possibility of such a property of protocells?

A) Allow fatty acids to self-assemble into protocells within solutions containing a mix of small molecules, then rinse the protocells and place them in pure water to observe whether they can carry out metabolic reactions.
B) Synthesize various protocells using different fatty acids, and compare their abilities to take up various different small molecules from the environment.
C) Place different molecules in the liquid medium surrounding living cells, and compare their rates of movement into the interiors of the cells.
D) Remove the internal structures of living cells, leaving only water and inorganic salts, and then place them into a broth of nutrient molecules and test their ability to develop metabolism.
E) Conduct a search for microfossils in which the movement of small molecules across primitive membranes is clearly observable in the specimens.