Amphipathic molecules can self-assemble into vesicles that concentrate reactants and maintain internal chemistry, providing a plausible compartment before fully living cells evolved.
Coverage 2015–2022 · Updated 15 Jul 2026
Vesicles can form spontaneously when amphipathic molecules arrange into a closed membrane-like boundary in water.
Hydrophilic parts face the water while hydrophobic parts cluster away from it, producing a bilayer or related compartment. A boundary can concentrate reactants and preserve gradients, making chemistry more effective and reducing dilution.
For a compartment to help, it needs:
A fatty-acid vesicle can enclose a catalyst and keep its reactants nearby, increasing the chance of repeated reactions.
A vesicle is not automatically a living cell; it still needs sustained chemistry, information and reproduction.
This objective is assessed through structured response, multiple choice, commonly using State / Identify.
State / Identify
Build the answer around this relationship: Amphipathic molecules can self-assemble in water.
Treating protobionts as complete modern cells with nuclei and organelles.
Representative question
State the name for primitive, phospholipid-enclosed structures that may have preceded cells.
A2.1 is usually tested as a connected argument, not as isolated facts. A strong answer builds a chain: early Earth conditions made abiotic organic synthesis plausible; origin models require small molecules, polymers, self-replication, and membranes; experiments and models support parts of the chain; LUCA, dating, and vents provide later evidence and constraints. The highest-scoring habit is to say “supports” when evidence supports, and avoid saying “proves” when it does not.
