Question

Are there modeling experiments to suggest that "hydrothermal synthesis" of fatty acid and other such molecules (that are prerequisites for membrane formation) is possible in regions of high pressure and temperature from simple compounds like hydrogen and carbon monoxide on the surface of catalysts like transition metal mineral sulfides or oxides?

Answer 1

Hydrothermal synthesis at deep-sea vents provides a catalytic environment for the creation of organic molecules from inorganic compounds. Catalysts such as transition metal sulfides and oxides facilitate the formation of prebiotic molecules necessary for life. Phospholipid self-assembly into micelles indicates the potential for primitive membrane formation in such conditions.

Step-by-step explanation:

The possibility of hydrothermal synthesis for the formation of essential biomolecules like fatty acids aligns closely with the hypotheses surrounding the origins of life on Earth. The conditions at deep-sea hydrothermal vents, including those that are volcanic or alkaline, are rich in reducing molecules and metals, providing a conducive environment for catalysis. The transition metal mineral sulfides and oxides present in these regions serve as catalysts, aiding in organic molecule synthesis from inorganic precursors like hydrogen and carbon monoxide.

Experimental evidence suggests that such environments could feasibly support the synthesis of membrane precursors. For example, experiments support the notion that iron-sulfur aggregates in hydrothermal vents may catalyze the formation of simple organic molecules from gases such as CO₂, CH₄, and NH₃. Additionally, in an aqueous environment, phospholipids exhibit the natural tendency to form membrane-like structures such as micelles, suggesting that the basic components for life could self-assemble under prebiotic conditions. These micelles and other primitive membrane structures are important due to their semi-permeability and potential role in early cellular compartmentalization.

Lastly, the fluidity of biological membranes, critical for cellular function, depends upon the saturation level of fatty acids, which can be influenced by environmental temperatures. In response to temperature changes, living organisms adapt the saturation level of membrane fatty acids to maintain membrane fluidity and integrity. Extrapolating from this, one could infer that the first forms of life may have emerged under conditions that supported the optimal balance of membrane fluidity necessary for survival.