Life Depends upon Two Kinds of Water

Abstract

BackgroundMany well-documented biochemical processes lack a molecular mechanism. Examples are: how ATP hydrolysis and an enzyme contrive to perform work, such as active transport; how peptides are formed from amino acids and DNA from nucleotides; how proteases cleave peptide bonds, how bone mineralises; how enzymes distinguish between sodium and potassium; how chirality of biopolymers was established prebiotically.Methodology/Principal FindingsIt is shown that involvement of water in all these processes is mandatory, but the water must be of the simplified configuration in which there are only two strengths of water-water hydrogen bonds, and in which these two types of water coexist as microdomains throughout the liquid temperature range. Since they have different strengths of hydrogen bonds, the microdomains differ in all their physical and chemical properties. Solutes partition asymmetrically, generating osmotic pressure gradients which must be compensated for or abolished. Displacement of the equilibrium between high and low density waters incurs a thermodynamic cost which limits solubility, depresses ionisation of water, drives protein folding and prevents high density water from boiling at its intrinsic boiling point which appears to be below 0°C. Active processes in biochemistry take place in sequential partial reactions, most of which release small amounts of free energy as heat. This ensures that the system is never far from equilibrium so that efficiency is extremely high. Energy transduction is neither possible and nor necessary. Chirality was probably established in prebiotic clays which must have carried stable populations of high density and low density water domains. Bioactive enantiomorphs partition into low density water in which they polymerise spontaneously.Conclusions/SignificanceThe simplified model of water has great explanatory power.

Is KELEA (Kinetic Energy Limiting Electrostatic Attraction) A Source Of Chemical Energy?

“…27 The water molecules in these domains are either loosely bonded (low-density) or more tightly bonded (high-density) bonded water molecules. The water in the low-density domains is proposed as having more energy than the water in the high-density domains.…”

Modulating Nucleation by Kosmotropes and Chaotropes: Testing the Waters

“…The model suggests that liquid water consists of rapidly exchanging high and low density micro-domains, and the equilibrium between these domains can be altered by dissolved solutes [18,55]. This is supported by distinct elution profiles for glucose enantiomers, suggested to involve micro-domain equilibrium shifts, wherein the bioactive enantiomer prefers a less dense aqueous environment and L-glucose favors a more dense water state [55]. Based on this hypothesis, the individual enantiomers are expected to have distinct effects on nucleation independent of solution pH.…”

“…The additives tested are betaine, ectoine, trehalose, sorbitol, mannitol, glycine, urea, thiourea, and guanidium. With reports of the stereoisomers of mono-and oligo-saccharides in chaotropic and kosmotropic behavior [55], D-and L-forms of sugars are also investigated. The analytical approach involves potentiometric titrations performed by dosing calcium chloride into a solution of an additive dissolved in carbonate buffer.…”

LIQUID CRYSTALLINE WATER, QUANTUM MOLECULAR MACHINES & THE LIVING STATE

“…According to Philippa Wiggins, high density water and low density water has preferential affinities for kosmotropes and chaotropes respectively [23,24]. Wiggins has further suggested that the spontaneous inter-conversion of these two forms of water in microdomains inside cells or enzyme active sites may be what gives life its seemingly boundless 'free energy'.…”