________ Formed the Semipermeable Membrane-Like Surfaces for the Earliest Life

Question

________ formed the semipermeable membrane-like surfaces for the earliest life forms.
A) Proteins
B) Hydrogen sulfide
C) Lipid bilayers
D) RNA

Accepted Answer

Lipid bilayers are the most likely to have formed the semipermeable membrane-like surfaces for the earliest life forms. Lipid molecules can self-assemble into a bilayer structure in water, where the hydrophilic heads face outward and the hydrophobic tails are shielded inside, creating a barrier that allows some molecules to pass through while blocking others. This property would have been crucial for the emergence of living cells, allowing them to maintain a distinct internal environment and interact selectively with their surroundings. Proteins and RNA are essential components of modern cells but are not thought to have been present in the simplest proto-cells, while hydrogen sulfide is not a likely candidate for forming cellular membranes.