核心概念
The specificity and entropy of product distributions in molecular templating networks are bounded by the free-energy differences along pathways that create and destroy the products, regardless of the complexity of the underlying reaction network.
要約
The content discusses the thermodynamic constraints on the distribution of products in molecular templating networks, where multiple distinct products can be selectively produced from a shared set of input molecules using catalytic templates.
Key highlights:
- The steady-state concentrations of the products are bounded by the free-energy changes along the pathways that create and destroy each product, even if the underlying reaction network is complex.
- The distribution that maximizes the probability of a single product (specificity maximization) is generally different from the distribution that minimizes the entropy of the product ensemble (entropy minimization).
- For a large number of possible products M, perfect specificity for a single product in steady state requires a free-energy difference between pathways ∆G > ln M, but even for ∆G << ln M, a vanishingly small fraction of the possible products can dominate the ensemble.
- The optimal system that minimizes the entropy of the product distribution is a "pseudo-equilibrium" one, where each product is coupled to a single dominant pathway, rather than a system that systematically assembles and degrades products.
- The bounds derived apply to the steady-state distribution, but arbitrary precision can be achieved at finite times without requiring large ∆G.