Decomposition Of Glycine Research Articles

Glycine-Induced Phosphorylation Plays a Pivotal Role in Energy Metabolism in Roots and Amino Acid Metabolism in Leaves of Tea Plant.

Phosphorylation is the most extensive post-translational modification of proteins and thus regulates plant growth. However, the regulatory mechanism of phosphorylation modification on the growth of tea plants caused by organic nitrogen is still unclear. In order to explore the phosphorylation modification mechanism of tea plants in response to organic nitrogen, we used glycine as the only nitrogen source and determined and analyzed the phosphorylated proteins in tea plants by phosphoproteomic analysis. The results showed that the phosphorylation modification induced by glycine-supply played important roles in the regulation of energy metabolism in tea roots and amino acid metabolism in tea leaves. In roots, glycine-supply induced dephosphorylation of proteins, such as fructose-bisphosphate aldolase cytoplasmic isozyme, glyceraldehyde-3-phosphate dehydrogenase, and phosphoenolpyruvate carboxylase, resulted in increased intensity of glycolysis and decreased intensity of tricarboxylic acid cycle. In leaves, the glycine-supply changed the phosphorylation levels of glycine dehydrogenase, aminomethyltransferase, glutamine synthetase, and ferredoxin-dependent glutamate synthase, which accelerated the decomposition of glycine and enhanced the ability of ammonia assimilation. In addition, glycine-supply could improve the tea quality by increasing the intensity of amino acids, such as theanine and alanine. This research clarified the important regulatory mechanism of amino acid nitrogen on tea plant growth and development through protein phosphorylation.

Decarboxylation of glycine on icy grain surfaces: a first-principle investigation

ABSTRACT Much effort has been devoted to the investigation of the reactivity of glycine, the smallest amino acid, in different environments in the interstellar medium (ISM). While the formation paths are expected to follow a gas-solid mechanism, the full picture of glycine survival in the ISM remains yet unrevealed. In this work, we have adopted density functional theory under periodic boundary conditions to simulate mechanisms for the decarboxylation of glycine on a water-rich surface and on a glycine ice. We have performed calculations at the PBE-D3/USPP level, from which several adsorption modes of glycine on each surface were investigated and decomposition mechanisms into CO2 and CH3NH2 on the different interfaces were suggested. Most favourable adsorption sites of glycine have adsorption energies of −106.54 and −98.52 kJ mol−1 on the water ice and glycine ice, respectively. Glycine decomposes into CO2 and CH3NH2 through a two-step mechanism on the water ice and four-step mechanism on the glycine surface, from which the barrier heights of the determinant steps were of 288.98 and 111.58 kJ mol−1, respectively. At temperatures of 50 K, decomposition of glycine into CO2 and CH3NH2 is an exergonic reaction, pointing to a thermodynamically controlled reaction in specific interstellar regions, such as hot-cores. Compared with reported glycine gas-phase reaction, much lower barrier heights for glycine formation were found in the surface models studied here.

Hyperstoichiometric Uranium Dioxides: Rapid Synthesis and Irradiation-Induced Structural Changes.

Uranium dioxide (UO2), the primary fuel for commercial nuclear reactors, incorporates excess oxygen forming a series of hyperstoichiometric oxides. Thin layers of these oxides, such as UO2.12, form readily on the fuel surface and influence its properties, performance, and potentially geologic disposal. This work reports a rapid and straightforward combustion process in uranyl nitrate-glycine-water solutions to prepare UO2.12 nanomaterials and thin films. We also report on the investigation of the structural changes induced in the material by irradiation. Despite the simple processing aspects, the combustion synthesis of UO2.12 has a sophisticated chemical mechanism involving several exothermic steps. Raman spectroscopy and single-crystal X-ray diffraction (XRD) measurements reveal the formation of a complex compound containing the uranyl moiety, glycine, H2O, and NO3- groups in reactive solutions and dried combustion precursors. Combustion diagnostic methods, gas-phase mass spectroscopy, differential scanning calorimetry (DSC), and extracted activation energies from DSC measurements show that the rate-limiting step of the process is the reaction of ammonia with nitrogen oxides formed from the decomposition of glycine and uranyl nitrate, respectively. However, the exothermic decomposition of the complex compound determines the maximum temperature of the process. In situ transmission electron microscopy (TEM) imaging and electron diffraction measurements show that the decomposition of the complex compound directly produces UO2. The incorporation of oxygen at the cooling stage of the combustion process is responsible for the formation of UO2.12. Spin coating of the solutions and brief annealing at 670 K allow the deposition of uniform films of UO2.12 with thicknesses up to 300 nm on an aluminum substrate. Irradiation of films with Ar2+ ions (1.7 MeV energy, a fluence of up to 1 × 1017 ions/cm2) shows unusual defect-simulated grain growth and enhanced chemical mixing of UO2.12 with the substrate due to the high uranium ion diffusion in films. The method described in this work allows the preparation of actinide oxide targets for fundamental nuclear science research and studies associated with stockpile stewardship.

Effects of aging time in hydrogen peroxide-glycine-based Cu CMP slurry

Hydrogen peroxide is widely used as an oxidizer in metal chemical mechanical planarization (CMP) slurry due to its strong oxidizing ability and being a non-metal product. However, hydrogen peroxide is unstable and easily decomposes into water and oxygen molecules. In this experiment, the aging of a hydrogen peroxide-glycine-based Cu CMP slurry was investigated in terms of the chemical concentration and CMP performance. Ultraviolet–visible–near-infrared spectroscopy was used to measure the change of hydrogen peroxide concentration with slurry aging. As the slurry aging time was increased, the removal rate decreased for several reasons. With slurry aging, not only decreases of hydrogen peroxide concentration but also decreases of pH and glycine decomposition were observed. Therefore, the removal rate was suppressed due to complex factors, including the decreased oxidizing ability with decreased hydrogen peroxide concentration, decomposition of the glycine chelating agent, and decrease in pH. This study suggests the necessity of monitoring slurry aging and management for optimizing CMP process performance.

Pulsed Discharge Plasma in High-Pressure Environment for Water Pollutant Degradation and Nanoparticle Synthesis

The application of high-voltage discharge plasma for water pollutant decomposition and the synthesis of nanoparticles under a high-pressure argon gas environment (~4 MPa) was demonstrated. The experiments were carried out in a batch-type system at room temperature with a pulsed DC power supply (15.4 to 18.6 kV) as a discharge plasma source. The results showed that the electrode materials, the pulsed repetition rates, the applied number of pulses, and the applied voltages had a significant effect on the degradation reactions of organic compounds. Furthermore, carbon solid materials from glycine decomposition were generated during the high-voltage discharge plasma treatment under high-pressure conditions, while Raman spectra and the HRTEM images indicated that titanium dioxide with a brookite structure and titanium carbide nanoparticles were also formed under these conditions. It was concluded that this process is applicable in practice and may lead to advanced organic compound decomposition and metal-based nanoparticle synthesis technologies.

An automated apparatus for the simulation of prebiotic wet‒dry cycles under strictly anaerobic conditions

AbstractPrebiotic chemical evolution on the early Earth may have been driven in part by fluctuating environments, for example wet‒dry and temperature cycling in volcanic rock pools. Here, we describe the setup, operating principle and test applications of a newly developed ‘wet‒dry apparatus’ (WDA) designed to simulate such fluctuating environments. The WDA allows adjusting the duration of the cycles, the temperature during the wet and dry phases and the organic and mineral components, which are all key parameters in wet–dry simulations. The WDA's most important features, however, are (i) that it is automated, which means that long-time experiments are possible without the need for an operator and (ii) that the virtual absence of free oxygen in the early Earth's atmosphere at ground level can be simulated. Rigorously oxygen-free conditions were achieved by passing 99.999% nitrogen gas through two alkaline pyrogallol solutions in series, prior to entering the WDA. We used three chemical systems to test the WDA: (i) the amino acid glycine in the presence and absence of clay minerals, (ii) linoleic acid (an oxygen-sensitive amphiphile) with and without the mineral olivine, and (iii) alkaline pyrogallol solution. We observed that clay minerals greatly accelerated the decomposition of glycine under wet‒dry conditions. Glycine peptides were formed as minor products. In the course of the glycine experiments, we developed a reliable gas chromatographic method to quantify the cyclic dipeptide 2,5-diketopiperazine. The decomposition of linoleic acid in wet‒dry cycles was promoted by both air and olivine. And finally, the extremely oxygen-sensitive pyrogallol solution was used as a colour indicator for residual oxygen in the WDA. The simulation facility in our laboratory currently consists of eight identical WDAs and a surrounding infrastructure. It can be made available to others who wish to perform cyclic wet–dry experiments.

Synthesis, Characterization and Analysis of Leishmanicide Ability of the Compound [Ru(Cl)<sub>3</sub>(H<sub>2</sub>O)<sub>2</sub>(gly)

Studies of coordinated compounds containing ruthenium (Ru2+ and Ru3+) have shown very effective in vitro results for the treatment of cancer and neglected diseases such as leishmaniasis. In this paper, we present the synthesis of the compound [Ru(Cl)3(H2O)2(gly)], which was characterized by spectroscopic (Ultraviolet-visibleand infrared) and thermal analysis (Thermogravimetry/Derived Thermogravimetry and Thermogravimetry/Differential Thermal Analysis). The analysis of the compound in the Ultraviolet-visibleregion showed a 290 nm band λmax (ε= 1.685 × 103 L·cm-1·mol-1), attributed to the ligand metal charge transfer (LMCT). The spectroscopy (IR) showed major vibrational bands at δa (-COO-) 1664 cm-1, δs (-COO-) 1388 cm-1, δs () 1571 cm-1 and δs (CCN) 889 cm-1. The thermal analysis by TG/DTG and TG-DTA indicated that the complex has five consecutive stages of decomposition: at 115°C (TG = 12.18%; Calculated = 11.32%) H2O (coordinating water), exothermic peaks at 230°C, 307°C, 440°C and 463°C due to oxidative decomposition of glycine, followed by the formation of RuClO residue at 665°C (TG = 41.11%; Calculated = 40.81%). The thermal characterization suggested the stoichiometry of the complex [RuCl3(H2O)2(gly)]. The antileishmanial capacity of this compound was also evaluated and the results indicated a 31% decrease in the parasitic infection of macrophages and a 1.5 to 3 fold reduction in the number of parasites per cell after treatment with 100 μg/mL of the complex. These results support the possible use of this compound as a therapeutic alternative against medical and veterinary parasites.

EFFECT OF PERCHLORATES ON ELECTRON RADIOLYSIS OF GLYCINE WITH APPLICATION TO MARS

ABSTRACT This work explores the radiolytic decomposition of glycine (H2NCH2COOH) under simulated Martian conditions in the presence of perchlorates ( ), which are abundant oxidizers on the surface of Mars, by energetic electrons at 10, 160, 210, and 260 K, mimicking the radiation exposure of the Martian regolith in the first 5–10 cm depths over about 250 million years. Our experiments present quantitative evidence that the rate constants of the glycine decomposition in the presence of magnesium perchlorate hexahydrate (Mg(ClO4)2 · 6H2O) were a factor of about two higher than that of the pure glycine, suggesting that energetic oxygen atoms (O) released from the have a significant effect on the decomposition rates and accelerate them by providing a unique oxidizing environment in the radiolyzed samples. Hence, two decay mechanisms exist: radiolysis by the electrons and oxidation by the O atoms. Within the Mars-relevant temperature range covering 160–260 K, the destruction rates are nearly temperature invariant with rates varying as little as 5%. Further, the formation rates of carbon dioxide (CO2) and carbon monoxide (CO) are both accelerated in the presence of by a factor of three to five, supporting our conclusion of an active oxygen-initiated chemistry. In addition, the degradation rates are significantly higher than the formation rates of CO2 and CO. This suggests that, besides the decarboxylation, alternative degradation pathways such as a polymerization of glycine must exist. Finally, besides CO2 and CO, three alternative products were identified tentatively: methylamine (CH3NH2), methane (CH4), and ammonia (NH3).

Study by Use of 1H NMR Spectroscopy of the Adsorption and Decomposition of Glycine, Leucine, and Derivatives in TiO2 Photocatalysis.

The photocatalytic decomposition and adsorption of glycine (Gly), Gly-Gly, and Gly-Gly-Gly, and leucine (Leu), Leu-Gly, Gly-Leu, and Leu-Gly-Gly, in TiO2 (100% anatase crystal form) aqueous suspension were investigated by 1H NMR spectroscopy. The side chain of Leu, the carboxylic group, and the peptide bond were recognized as the adsorptive sites of the peptides on the surface of TiO2. For Gly-Leu and Leu-Gly-Gly, the photocatalytic decomposition that took place under UV irradiation resulted from the preferable adsorption of the hydrophobic side chain of Leu on the TiO2 surface, while for Gly-Gly and Gly-Gly-Gly, the photodecomposition proceeded by weak adsorption of the peptide bonds on the surface of TiO2.

The temperature effect on the glycine decomposition induced by 2 keV electron bombardment in space analog conditions

Glycine is the simplest proteinaceous amino acid that has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA’s Stardust spacecraft. In space, such species is exposed to several radiation fields at different temperatures. In aqueous solutions, this species appears mainly as zwitterionic glycine (+NH3CH2COO−) however, in solid phase, it may be found in amorphous or crystalline forms. Here, we present an experimental study on the destruction of two zwitterionic glycine crystals (α- and β-form) at two different temperatures (300 K and 14 K) by 2 keV electrons in an attempt to test the behavior and stability of this molecular species in different space environments. The samples were analyzed in situ by Fourier transform infrared spectrometry at electron fluences. The experiments were carried out under ultra-high vacuum conditions at the Molecular Physics Laboratory at the Open University at Milton Keynes, UK. The dissociation cross section of glycine is approximately 5 times higher for the 14 K samples when compared to the 300 K samples. In contrast, no significant differences emerged between the dissociation cross sections of α- and β-forms of glycine for fixed temperature experiments. We therefore conclude that the destruction cross section is more heavily dependent on temperature than the phase of the condensed glycine material. This may be associated with the opening of additional reaction routes in the frozen samples involving the trapped daughter species (e.g. CO2 and CO). The half-life of studied samples extrapolated to space conditions shows that glycine molecules on the surface of interstellar grains has less survivability and they are highly sensitive to ambient radiations, however, they can survive extended period of time in the solar system like environments. Survivability increases by a factor of 5 if the samples are at 300 K when compared to low temperature experiments at 14 K and is independent of the crystalline structure. In addition, this survival would increase if the molecular species were protected by several layers of other molecular species as trapped in comet mantles or embedded within regolith in asteroids/lunar surfaces. The understanding of the excitation and dissociation processes of organic compounds in space simulation is highly required to put constrains in the puzzle over the origin of life in the primitive Earth.

The Influence of Crystallinity Degree on the Glycine Decomposition Induced by 1 MeV Proton Bombardment in Space Analog Conditions

Glycine is the simplest proteinaceous amino acid and is present in all life-forms on Earth. In aqueous solutions, it appears mainly as zwitterion glycine (+NH3CH2COO-); however, in solid phase, it may be found in amorphous or crystalline (α, β, and γ) forms. The crystalline forms differ from each other by the packing of zwitterions in the unitary cells and by the number of intermolecular hydrogen bonds. This molecular species has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA's Stardust spacecraft. In space, glycine is exposed to several radiation fields at different temperatures. We present an experimental study on the destruction of zwitterionic glycine crystals at room temperature by 1 MeV protons, in which the dependence of the destruction rates of the α-glycine and β-glycine crystals on bombardment fluence is investigated. The samples were analyzed in situ by Fourier transform infrared spectrometry at different proton fluences. The experiments occurred under ultrahigh vacuum conditions at the Van de Graaff accelerator lab at the Pontifical Catholic University at Rio de Janeiro (PUC-Rio), Brazil. For low fluences, the dissociation cross section of α-glycine was observed to be 2.5×10(-14) cm2, a value roughly 5 times higher than the dissociation cross section found for β-glycine. The estimated half-lives of α-glycine and β-glycine zwitterionic forms extrapolated to the Earth orbit environment are 9×10(5) and 4×10(6) years, respectively. In the diffuse interstellar medium the estimated values are 1 order of magnitude lower. These results suggest that pristine interstellar β-glycine is the one most likely to survive the hostile environments of space radiation. A small feature around 1650-1700 cm(-1), tentatively attributed to an amide functional group, was observed in the IR spectra of irradiated samples, suggesting that cosmic rays may induce peptide bond synthesis in glycine crystals. Combining this finding with the fact that this form has the highest solubility among the other glycine polymorphs, we suggest that β-glycine is the one most likely to have produced the first peptides on primitive Earth.

On the mechanism and rate of spontaneous decomposition of amino acids.

Spontaneous decarboxylation of amino acids is among the slowest known reactions; it is much less facile than the cleavage of amide bonds in polypeptides. Establishment of the kinetics and mechanisms for this fundamental reaction is important for gauging the proficiency of enzymes. In the present study, multiple mechanisms for glycine decomposition in water are explored using QM/MM Monte Carlo simulations and free energy perturbation theory. Simple CO(2) detachment emerges as the preferred pathway for decarboxylation; it is followed by water-assisted proton transfer to yield the products: CO(2) and methylamine. The computed free energy of activation of 45 kcal/mol, and the resulting rate-constant of 1 × 10(-21) s(-1), can be compared with an extrapolated experimental rate constant of ~2 × 10(-17) s(-1) at 25 °C. The half-life for the reaction is more than 1 billion years. Furthermore, examination of deamination finds simple NH(3)-detachment yielding α-lactone to be the favored route, though it is less facile than decarboxylation by 6 kcal/mol. Ab initio and DFT calculations with the CPCM hydration model were also carried out for the reactions; the computed free energies of activation for glycine decarboxylation agree with the QM/MM result, whereas deamination is predicted to be more favorable. QM/MM calculations were also performed for decarboxylation of alanine; the computed barrier is 2 kcal/mol higher than for glycine in qualitative accord with experiment.

Solution combustion synthesis of metal nanopowders: Nickel—Reaction pathways

AbstractNanopowders of pure nickel were directly synthesized for the first time by conventional solution combustion synthesis (SCS) method. In this article, a specific reaction pathway is suggested to describe the metallic phase formation during SCS. It is proposed that the exothermic reaction between NH3 and HNO3 species formed during the decomposition of glycine and nickel nitrate acts as the source of energy required to achieve the self‐sustained reaction regime. A thermodynamic analysis of the combustion synthesis reaction indicates that increasing glycine concentration leads to establishing a hydrogen rich reducing environment in the combustion wave that in turn results in the formation of pure metals and metal alloys. TGA of reaction systems and XRD analysis of products in the quenched combustion wave show that the formation of oxide phases occurs in the reaction front, followed by gradual reduction of oxide to pure metallic phases in the postcombustion zone. A methodology for SCS of pure metals and metal alloys nanoparticles can be inferred from the results presented. © 2010 American Institute of Chemical Engineers AIChE J, 2011

Studies of the rates of thermal decomposition of glycine, alanine, and serine

Rates of thermal decomposition of glycine, alanine, and serine are described by the equation of first order reaction in the temperature range 200–300°C. Apparent rate constants and apparent activation energies of decomposition of α-amino acids were evaluated. It was found that the main gaseos reaction product is carbon dioxide.

Comparative Theoretical and Experimental Study of the Radiation-Induced Decomposition of Glycine

The radiation-induced decomposition of glycine is studied using a combination of near-edge X-ray absorption fine structure (NEXAFS) measurements and DFT calculations. The measured spectra show strong dose- or time-dependent effects consistent with a complex, multistep decomposition. Principal component analysis was used to determine the number of distinct molecules that were needed to explain the observed changes in the measured spectra, and the emerging absorption features are assigned to various product molecules through comparison with simulated spectra of several model compounds. It is clear from the experiment that the major effect of soft X-ray irradiation is the fragmentation of the molecule, primarily at the carbonyl sites. Peptide formation is shown to occur under irradiation; a condensation reaction initiated by the removal of a carbonyl oxygen is the proposed mechanism. This study utilizes a novel approach to the study of radiation damage that can occur during measurements and suggests that it may be possible to use simulated model spectra to correct for these effects in measured spectra.

Hydrothermal reactions of alanine and glycine in sub- and supercritical water

The decomposition of the amino acids alanine and glycine as model compounds for proteins was studied in sub- and supercritical water. Experiments were carried out in a continuous high pressure plant with a feed solution of 1.0 and 2.0% (g g −1) amino acid at 250–450 °C, 34 and 24 MPa and residence times of 2.5–35 s. The effect of temperature, residence time, pressure and reactant concentration on conversion and yields of reaction products was elucidated. Based on experimental results reaction networks with the main reactions amino acid decarboxylation and amino acid deamination were formulated for both reactants. Amino acid decomposition kinetics could be described satisfyingly by simple global rate laws. Activation energies are for the alanine decomposition 160 kJ mol −1 and for the glycine decomposition 156 kJ mol −1.

Evaluate the pyrolysis pathway of glycine and glycylglycine by TG–FTIR

An online-coupled TG–FTIR evolved gas analysis (EGA) instruments has been used to identify and monitor the evolution of gaseous products during thermal decomposition of glycine and its dipeptide in flowing N 2 atmosphere up to 800 °C. The first gaseous products of glycine pyrolysis, evolved around 260 °C are NH 3, H 2O and CO 2. The max releasing rates of both NH 3 and H 2O are reached at 282 °C and that of CO 2 is reached at 308 °C. At 400 °C HNCO becomes the main product, accompanied by CO, HCN and some other species. HCN is the main gaseous species released around 700 °C. Compared with glycine, glycylglycine has lower thermal stability, which begins to decompose at 214 °C. However, that the evolution profiles of gaseous products from glycine and glycylglycine are similar, which suggests the decomposition of them may occur through similar pathways. Our results indicate that the primary decomposition steps include deamination and dehydration. CO 2 is mainly formed through the secondary reactions. And the crack of cyclic amide, 2,5-diketopiperazine (DKP), is suggested to be the main origin of HNCO and HCN at higher temperature.

Potential net soil N mineralization and decomposition of glycine- 13C in forest soils along an elevation gradient

The objective of this research was to better understand patterns of soil nitrogen (N) availability and soil organic matter (SOM) decomposition in forest soils across an elevation gradient (235–1670 m) in the southern Appalachian Mountains. Laboratory studies were used to determine the potential rate of net soil N mineralization and in situ studies of 13C-labelled glycine were used to infer differences in decomposition rates. Nitrogen stocks, surface soil (0–5 cm) N concentrations, and the pool of potentially mineralizable surface soil N tended to increase from low to high elevations. Rates of potential net soil N mineralization were not significantly correlated with elevation. Increasing soil N availability with elevation is primarily due to greater soil N stocks and lower substrate C-to-N ratios, rather than differences in potential net soil N mineralization rates. The loss rate of 13C from labelled soils (0–20 cm) was inversely related to study site elevation ( r=−0.85; P<0.05) and directly related to mean annual temperature (+0.86; P<0.05). The results indicated different patterns of potential net soil N mineralization and 13C loss along the elevation gradient. The different patterns can be explained within a framework of climate, substrate chemistry, and coupled soil C and N stocks. Although less SOM decomposition is indicated at cool, high-elevation sites, low substrate C-to-N ratios in these N-rich systems result in more N release (N mineralization) for each unit of C converted to CO 2 by soil microorganisms.

Reaction behaviors of glycine under super- and subcritical water conditions.

The influence of temperature and pressure on the dimerization and decomposition of glycine under simulated hydrothermal system conditions was studied by injecting a glycine solution into water in the sub- and supercritical state. The experiments at five different temperatures of supplied water--250, 300, 350, 374, and 400 degrees C--were performed at 22.2 and 40.0 MPa. At 350 degrees C, experiments under 15.0-40.0 MPa were conducted. Diglycine, triglycine (trace), diketopiperazine, and an unidentified product with a high molecular mass (433 Da) were the main products of oligomerization. The results show that temperature and pressure influence the extent of dimerization and decomposition of glycine. The maximum of dimers formation was observed at 350 and 375 degrees C at 22.2 and 40.0 MPa, respectively, and coincided with a high rate of glycine decomposition. Glycine, alanine, aspartic acid, as well as other amino acids, were obtained by injecting a mixture of formaldehyde and ammonia. The results support the oligomerization and synthesis of amino acids in a submarine hydrothermal system.

Decomposition of Glycine in High Temperature and High Pressure Water.

グリシンの水熱反応に関する研究を，温度260～340°C，圧力30MPaの範囲で行った．グリシン分解による主な生成物は，アミン類，有機酸類および炭酸であることを確認した．これらの生成物から，高温高圧水中におけるグリシンの分解は，脱アミノ反応と脱炭酸反応によって生じていることが示唆された．また，グリシンの分解速度は，実験条件の範囲内において，グリシンの濃度に一次反応として表すことができた．