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Published on: July 28, 2018
The chemical logic of a minimum protocell
H J Morowitz1, B Heinz, D W Deamer
1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511.
Summary
This study proposes minimum protocells: self-assembling membrane vesicles that capture light energy. This provides a photosynthetic growth process for early cellular life, offering an alternative origin of life model.
Area of Science:
- Origin of life research
- Astrobiology
- Biochemistry
Background:
- Traditional origin of life theories focus on polymer synthesis preceding cell formation.
- Existing models often overlook the crucial role of early membrane structures.
Purpose of the Study:
- To present an alternative model for the origin of cellular life based on replicating membrane vesicles.
- To define and explore the concept of 'minimum protocells' as a precursor to early cells.
Main Methods:
- Investigating self-assembling bilayer membranes from prebiotic organic amphiphiles.
- Analyzing the role of asymmetrically oriented primitive pigment molecules within these membranes.
- Modeling the capture of light energy to form electrochemical ion gradients.
Main Results:
- Demonstrated that membrane vesicles can self-assemble from available prebiotic compounds.
- Showcased how embedded pigment molecules can harness light energy for gradient formation.
- Proposed a mechanism for photosynthetic growth and microenvironment creation within protocells.
Conclusions:
- Minimum protocells, as replicating membrane vesicles, offer a viable alternative pathway for the origin of cellular life.
- Photosynthetic energy capture by protocells could precede complex polymer synthesis systems.
- This model provides a framework for understanding early cellular evolution and the development of life's essential components.
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