How hard is it to encapsulate life? The general constraints on encapsulation

Area of Science:

• Biophysics
• Origin of Life Studies
• Synthetic Biology

Background:

• Encapsulation is often studied for its benefits in early life.
• However, the physical and biochemical challenges of encapsulation are less understood.
• Understanding these constraints is crucial for origins of life and astrobiology.

Purpose of the Study:

• To investigate the general constraints and challenges of encapsulating biotic systems.
• To determine how molecular characteristics and reaction rates impact encapsulation.
• To provide a framework for understanding encapsulation limits in various biological contexts.

Main Methods:

• Analysis of Earth's extant biochemical system, focusing on ribosome size and rate.
• Modeling of generic autocatalytic systems and systems with separated informational/functional molecules.
• Examination of environmental loss rates and their effect on cell volume fractions.

Main Results:

• Small changes in macromolecule rates/sizes can impede encapsulation.
• Ribosome speed relative to size creates a threshold limiting modern life's encapsulation.
• Cellular growth rates are bounded by effective molecular rates and volume fractions.
• Environmental loss rates dictate allowable cell volume fractions based on catalytic rates.

Conclusions:

• Encapsulation presents significant biophysical challenges independent of its advantages.
• Macromolecular properties and environmental factors impose fundamental limits on cell size and growth.
• These findings have broad implications for understanding life's origins, astrobiology, and synthetic biology.