Kinetics of light emission by photosynthetic systems: Second order light decay kinetics means elovich kinetics in a solid state reaction; 1.5 order light decay kinetics means second order reaction kinetics

Kinetics of biological light emission processes do not mean what they seem to mean, because measured light intensity is not proportional to reactant concentration but to reaction rate. Therefore, the differential equation for light decay is usually different from that of concentration decay, so that mass action interpretations cannot be applied directly to light intensity decay. An observed second order light decay for Chlorella at 6.5°C, implies Elovich solid state reaction kinetics, which agrees with other evidence for solid state processes in photosynthesis. An observed 1.5 order light decay for Cholorella at 28°C implies second order liquid or solid state reaction kinetics. First ordere light decay implies first order reaction kinetics.     

A method for calculation of human systolic and diastolic blood pressures using an elastic reservoir theory of the systemic arterial system,and some clinical and physiological applications

Two equations have been developed that describe the interrelationship of the clinically measurable variables of the human systemic arterial system. An approximation method is given for their simultaneous solution for systolic and diastolic pressures in terms of heart rate, cardiac output, total peripheral resistance, and aortic distensibility. In this way, blood pressures were calculated for various clinically important and didactically useful situations. The effects on systolic and diastolic pressures due to changing either cardiac output or peripheral resistance or heart rate or aortic distensibility alone are shown. The effects on pulse pressure of varying cardiac output and peripheral resistance while holding mean arterial pressure constant are demonstrated. Compensatory mechanisms in hypertension and exercise are explored. Opinions and conclusions contained in this report are those of the author. They are not to be construed as necessarily reflecting the views or the endorsement of the Navy Department.     

A generalized theory of particulate electron conduction enzymes applied to cytochrome oxidase. A theory of coupled electron and/or ion transport applied to pyruvate carboxylase

A previously developed theory of particulate electron conduction enzymes was based on a model of an enzyme particle catalyzing the oxidation-reduction of two different substrates at two different enzymatic sites on the same particle with conduction of electrons between the two sites through the enzyme particle. Using the simplifying assumption that the percent reduction of the second substrate is held constant, there was previously shown to be a hyperbolic relationship between the first order rate constant (k′) and the sum (C _x ) of oxidized plus reduced substrate, of the formk′=α/(C _x +β), where α and β are positive constants. It is shown here that if this simplifying assumption is omitted, a positive constant is added to the right hand side of this equation, which describes exactly the experimental data of Smith and conrad on cytochrome oxidase. If electron transport is assumed to be coupled to ion transport, this equation becomesk′=(α/C _x )−γ (where γ is a positive constant) which describes the experimental data of Eadie and Gale on pyruvic carboxylase of yeast. It seems probable that the same theory is applicable to coupled ion-ion transport and coupled electron-electron transport in both membranous systems, and in particulate preparations consisting of membrane fragments.     

NMR Evidence for Complexing of Na+ in Muscle, Kidney, and Brain, and by Actomyosin. The Relation of Cellular Complexing of Na+ to Water Structure and to Transport Kinetics

The nuclear magnetic resonance (NMR) spectrum of Na⁺ is suitable for qualitative and quantitative analysis of Na⁺ in tissues. The width of the NMR spectrum is dependent upon the environment surrounding the individual Na⁺ ion. NMR spectra of fresh muscle compared with spectra of the same samples after ashing show that approximately 70% of total muscle Na⁺ gives no detectable NMR spectrum. This is probably due to complexation of Na⁺ with macromolecules, which causes the NMR spectrum to be broadened beyond detection. A similar effect has been observed when Na⁺ interacts with ion exchange resin. NMR also indicates that about 60% of Na⁺ of kidney and brain is complexed. Destruction of cell structure of muscle by homogenization little alters the per cent complexing of Na⁺. NMR studies show that Na⁺ is complexed by actomyosin, which may be the molecular site of complexation of some Na⁺ in muscle. The same studies indicate that the solubility of Na⁺ in the interstitial water of actomyosin gel is markedly reduced compared with its solubility in liquid water, which suggests that the water in the gel is organized into an icelike state by the nearby actomyosin molecules. If a major fraction of intracellular Na⁺ exists in a complexed state, then major revisions in most theoretical treatments of equilibria, diffusion, and transport of cellular Na⁺ become appropriate.     

A non-equilibrium thermodynamic theory of leakage of complexed Na+ from muscle,with NMR evidence that the non-complexed fraction of muscle Na+ is intra-vacuolar rather than extra-cellular

Recent experimental evidence has provided increasing support for the hypotheses that 60 to 80 per cent of intracellular Na⁺ exists in a complexed state, and that intracellular water exists in a semi-organized, non-liquid state having low solubility for Na⁺. Using these postulates, a previous crude theory of Na⁺ leakage from the cell based on electronion conduction analogies has been redeveloped in a more complete and detailed fashion, following a non-equilibrium thermodynamic approach. The theory, which is based on the postulate of almost 100 per cent complexing of intracellular Na⁺, predicts that Na⁺ leakage from muscle should conform to the Elovich equation, which closely agrees with experiment, despite the fact that experiments indicate that 20 to 40 per cent of muscle Na⁺ isnot complexed. To resolve this apparent paradox, the leakage of complexed and non-complexed Na⁺ from muscle was measured by nuclear magnetic resonance (NMR). The non-complexed Na⁺ leaked much more slowly than the complexed Na⁺, suggesting that the non-complexed Na⁺ may be confined within vacuoles surrounded by an activation energy barrier at the vacuolar membrane. This implies that the measured curves of Na⁺ leakage showing Elovich kinetics are due mostly to leakage of complexed Na⁺ as the theory requires, and that the leakage of 20 to 40 per cent non-complexed Na⁺ is mostly delayed until later times.