Enhanced Diffusion of Passive Tracers in Active Enzyme Solutions

Area of Science:

• Fluid dynamics
• Biophysics
• Chemical kinetics

Background:

• Colloidal suspensions with microscopic swimmers are studied for energy transfer at low Reynolds numbers.
• Active enzymes are nonequilibrium systems that generate forces, enabling studies at the ultralow Reynolds number regime.

Purpose of the Study:

• To investigate energy transfer mechanisms in active enzyme solutions at the molecular level.
• To compare energy transfer in enzyme systems with larger microscopic active systems.

Main Methods:

• Monitoring the diffusion of inert tracers dispersed in active enzyme solutions.
• Analyzing tracer diffusion to understand energy transfer dynamics.

Main Results:

• Active enzyme solutions exhibit energy transfer characteristics similar to larger microscopic active systems.
• Enhanced tracer diffusion was observed even with enzymes catalyzing endothermic reactions.
• Heat generation was found not to be the primary driver of enhanced tracer diffusion.

Conclusions:

• The nature of energy transfer in active enzyme systems parallels that of larger microscopic active systems, despite scale and mechanism differences.
• Energy transfer at the molecular level in enzyme systems is not solely dependent on heat generation.
• The study provides novel insights into molecular-level energy transfer mechanisms in active systems.