scholarly journals Factors Which Influence the Acquisition of Flagella by the Amoeba, Naegleria Gruberi

1956 ◽  
Vol 33 (3) ◽  
pp. 583-603
Author(s):  
E. N. WILLMER
Keyword(s):  
Sodium Bicarbonate ◽  
Sodium Phosphate ◽  
Sodium Lactate ◽  
Lithium Salts ◽  
Distilled Water ◽  
Free Swimming ◽  
Low Concentrations ◽  
Amoeboid Form ◽  
Optimum Ph ◽  
Naegleria Gruberi

1. When placed in distilled water Naegleria gruberi changes from an amoeboid organism, with little evidence of polarity, to a highly polarized free-swimming flagellate. The details of this metamorphosis are described. The change is reversible. 2. Alteration of osmotic pressure is not in itself the direct cause of the metamorphosis, though the loss of certain ions is clearly important. 3. The metamorphosis is favoured by the presence of low concentrations (less than M/80) of sodium bicarbonate, sodium lactate and sodium phosphate. 4. The flagellate form probably occurs most frequently in conditions of neutrality; but, in the presence of phosphate, acid conditions tend to be more favourable to the flagellate form, while in the presence of bicarbonate the optimum pH is nearer pH 8.0. 5. The metamorphosis to the flagellate form is suppressed by a variety of agents including lithium salts, magnesium chloride and the sulphate ion under some conditions. These all act at concentrations which leave the amoeboid form in full activity. In some cases their action is decreased by the presence of bicarbonate in the medium.

scholarly journals Further Observations on the ‘Metaplasia’ of an Amoeba, Naegleria gruberi

Development ◽  
1958 ◽  
Vol 6 (2) ◽  
pp. 187-214
Author(s):  
E. N. Willmer
Keyword(s):  
Turning Points ◽  
External Environment ◽  
Distilled Water ◽  
Ionic Balance ◽  
Critical Concentrations ◽  
Amoeboid Form ◽  
Simple Movement ◽  
Naegleria Gruberi

The development of flagella by Naegleria gruberi, which occurs when a culture of organisms in the amoeboid form is treated with distilled water, has been shown (Willmer, 1956) to be a phenomenon probably related more to the ionic balance between the organism and its external environment than to the simple movement of water in and out of the cell in response to total osmotic changes. From Text-fig. 1 it may be seen that with respect to the response of the amoeba to different concentrations of the various salts investigated there are for each salt two somewhat critical concentrations. In the case of NaCl solutions in distilled water these turning points occur at about 30 mM. and 1 mM., and in the case of KCl solutions at about 50 mM. and 6 mM. Above the higher of these concentrations in each case the organisms always assume the amoeboid form, and below the lower they become flagellate at least as frequently as they do in distilled water.

scholarly journals A shift in the optimum pH of phospholipase D produced by activating long-chain anions

1969 ◽  
Vol 112 (5) ◽  
pp. 795-799 ◽  
Author(s):  
R. H. Quarles ◽  
R. M. C. Dawson
Keyword(s):  
Phosphatidic Acid ◽  
Phospholipase D ◽  
Activity Profile ◽  
Ph Optimum ◽  
Surface Ph ◽  
Electrophoretic Mobilities ◽  
Low Concentrations ◽  
Optimum Ph ◽  
Long Chain

1. The activity of phospholipase D (phosphatidylcholine phosphatidohydrolase, EC 3.1.4.4) towards ultrasonically treated phosphatidylcholine or large phosphatidylcholine particles activated with ether was maximal near pH5, and there was little activity above pH6. 2. When the enzyme was activated by the addition of phosphatidic acid to large phosphatidylcholine particles the pH optimum was shifted to pH6·5 irrespective of the amount of activator added. 3. When the enzyme was activated with low concentrations of dodecyl sulphate the pH optimum was 5·5 with little activity above pH6. With higher concentrations of dodecyl sulphate the pH–activity profile was shifted upwards towards a pH optimum of 6·5–6·6, the magnitude of the shift depending on the extent of the hydrolysis. 4. The shifts in the pH–activity profiles cannot be correlated with changes in the ‘surface pH’ of the substrate particles calculated from the measurement of their ζ-potentials (electrophoretic mobilities).

scholarly journals Properties of pyruvate kinase and phosphoenolpyruvate carboxykinase in relation to the direction and regulation of phosphoenolpyruvate metabolism in muscles of the frog and marine invertebrates

1978 ◽  
Vol 174 (3) ◽  
pp. 979-987 ◽  
Author(s):  
Victor A. Zammit ◽  
Eric A. Newsholme
Keyword(s):  
Pyruvate Kinase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Marine Invertebrates ◽  
Adductor Muscle ◽  
Sea Anemone ◽  
Anaerobic Conditions ◽  
Fructose Bisphosphate ◽  
Low Concentrations ◽  
Optimum Ph ◽  
Hill Coefficients

1. The properties of pyruvate kinase and, if present, phosphoenolpyruvate carboxykinase from the muscles of the sea anemone, scallop, oyster, crab, lobster and frog were investigated. 2. In general, the properties of pyruvate kinase from all muscles were similar, except for those of the enzyme from the oyster (adductor muscle); the pH optima were between 7.1 and 7.4, whereas that for oyster was 8.2; fructose bisphosphate lowered the optimum pH of the oyster enzyme from 8.2 to 7.1, but it had no effect on the enzymes from other muscles. Hill coefficients for the effect of the concentration of phosphoenolpyruvate were close to unity in the absence of added alanine for the enzymes from all muscles except oyster adductor muscle; it was 1.5 for this enzyme. Alanine inhibited the enzyme from all muscles except the frog; this inhibition was relieved by fructose bisphosphate. Low concentrations of alanine were very effective with the enzyme from the oyster (50% inhibition was observed at 0.4mm). Fructose bisphosphate activated the enzyme from all muscles, but extremely low concentrations were effective with the oyster enzyme (0.13μm produced 50% activation). 3. In general, the properties of phosphoenolpyruvate carboxykinase from the sea anemone and oyster muscles are similar: the Km values for phosphoenolpyruvate are low (0.10 and 0.13mm); the enzymes require Mn2+ in addition to Mg2+ for activity; and ITP inhibits the enzymes and the inhibition is relieved by alanine. These latter compounds had no effect on enzymes from other muscles. 4. It is suggested that changes in concentrations of fructose bisphosphate, alanine and ITP produce a coordinated mechanism of control of the activities of pyruvate kinase and phosphoenolpyruvate carboxykinase in the sea anemone and oyster muscles, which ensures that phosphoenolpyruvate is converted into oxaloacetate and then into succinate in these muscles under anaerobic conditions. 5. It is suggested that in the muscles of the crab, lobster and frog, phosphoenolpyruvate carboxykinase catalyses the conversion of oxaloacetate into phosphoenolpyruvate. This may be part of a pathway for the oxidation of some amino acids in these muscles.

scholarly journals Comparison of the Cerumenolytic Activities of New and Currently Used Agents

2021 ◽  
pp. 014556132098606
Author(s):  
Nguyen Quynh Anh ◽  
Pawin Numthavaj ◽  
Thongchai Bhongmakapat
Keyword(s):  
Salicylic Acid ◽  
Sodium Bicarbonate ◽  
Potassium Hydroxide ◽  
Glycolic Acid ◽  
Statistical Significance ◽  
In Vitro Study ◽  
Distilled Water ◽  
Moderate Amount ◽  
All Solutions

Objectives: This study compared the cerumen dissolution activities of 7.5% sodium bicarbonate, 5% potassium hydroxide, 10% lactic acid, 3% salicylic acid, 10% glycolic acid, and distilled water. Methods: An in vitro study was conducted with 36 cerumen samples. The cerumenolytic activities of the 6 agents were assessed by recording the degree of cerumen disintegration using digital photography at 15 minutes, 30 minutes, 1 hour, 2 hours, and 12 hours. The undissolved cerumen that remained after 12 hours was removed from the solutions and weighed after drying. Results: Potassium hydroxide showed the fastest cerumenolytic activity, dissolving a moderate amount of cerumen at 30 minutes, while glycolic acid and salicylic acid caused no visible changes in the cerumen samples. Samples treated with potassium hydroxide and sodium bicarbonate exhibited higher degrees of disintegration compared to samples treated with distilled water (odds ratio and 95% CI: 273.237 [0.203-367 470.4] and 1.129 [0.002-850.341], respectively). The greatest reduction in cerumen weight was associated with the use of sodium bicarbonate; however, this result did not reach statistical significance. Conclusions: Among the solutions tested, 5% potassium hydroxide showed the fastest dissolution activity, yielding moderate disintegration within only 30 minutes. In terms of residual cerumen weight within 12 hours, all solutions exhibited equivalent effectiveness in the disintegration of cerumen.

Performance of Distilled Water Electrolysis with Adding of Sodium Bicarbonate as Catalytic

2016 ◽  
Vol 836 ◽  
pp. 294-298
Author(s):  
Denny Widhiyanuriyawan
Keyword(s):  
Sodium Bicarbonate ◽  
Chemical Compound ◽  
Mass Fraction ◽  
Water Electrolysis ◽  
Distilled Water ◽  
Chemical Formula ◽  
Electrolysis Process ◽  
Constituent Elements ◽  
Brown’S Gas

Water is a chemical compound with chemical formula H2O. By the electrolysis proses, water can be split constituent elements, namely hydrogen (H2) and oxygen (O2). In this study, an electrolyze system used six pieces of electrodes which made from 304L SS for electrolysis process for both of distilled water and adding catalyst NaHCO3 (Sodium Bicarbonate) on distilled water. The results indicated that electrolysis process on distilled water consumed power of 353.52 Watts to produce Brown’s gas of 0.00123 l/s. Whenever, NaHCO3 was added into distilled water with the mass fraction of 1.33% consumed power decrease of 27.89 Watts and Browns gas was produced 0.0017 l/s. The efficiency of distilled water had the greatest efficiency only 5.53% by using current of 2 Ampere and power reached 31.043Watts. While the addition of catalysts had the greatest efficiency reached 40.29% in the use of mass fraction of catalyst 1.5%, 6 Ampere currents and power of 19.829 Watts.

Observations on bud formation and proliferations on cytokinin-treated root segments of Ophioglossum petiolatum

1969 ◽  
Vol 47 (10) ◽  
pp. 1579-1583 ◽  
Author(s):  
R. L. Peterson
Keyword(s):  
Apical Cell ◽  
Root Apex ◽  
Leaf Primordia ◽  
Distilled Water ◽  
Water Control ◽  
Cortical Cells ◽  
Root Segments ◽  
Low Concentrations ◽  
High Concentrations ◽  
Intact Root

Root segments of the fern Ophioglossum petiolatum with either an intact root apex or with the apex removed were treated with distilled water (control) or a range of concentrations of kinetin or benzyladenine in aqueous solution. Buds initiated on segments treated with distilled water or low concentrations of cytokinins had an apical meristem consisting of an apical cell with derivatives and a few leaf primordia located immediately beneath an air cavity formed by the lysis of cortical cells of the parent root. There was little cortical proliferation associated with the initiation of these buds. However, application of cytokinins at relatively high concentrations induced considerable proliferation of root tissue and a concomitant organization of numerous apical meristems in this tissue. Each induced meristem was structurally similar to those initiated on control root segments or those treated with low concentrations of cytokinins with the exception that leaf primordia were not as readily visible. Groups of tracheid-like cells were present in the callus-like outgrowths and, in root segments treated with 10.0 mg/l kinetin, large starch-filled parenchyma cells were evident at the periphery of the proliferations.

A kinetic study of autohydrogenotrophic denitrification at the optimum pH and sodium bicarbonate dose

2010 ◽  
Vol 101 (7) ◽  
pp. 2236-2242 ◽  
Author(s):  
Shahin Ghafari ◽  
Masitah Hasan ◽  
Mohamed Kheireddine Aroua
Keyword(s):  
Sodium Bicarbonate ◽  
Kinetic Study ◽  
Optimum Ph

EFFECT OF BENZOIC ACID AND ITS DERIVATIVES ON PLANT METABOLISM: 6- EFFECT OF CHLOROBENZOIC ACID DERIVATIVES ON THE CARBOHYDRATE METABOLISM OF STARVED AND SUCROSE-FED ETIOLATED BARLEY LEAVES

1963 ◽  
Vol 41 (6) ◽  
pp. 939-946 ◽  
Author(s):  
M. I. Naguib
Keyword(s):  
Carbohydrate Metabolism ◽  
Distilled Water ◽  
Sucrose Uptake ◽  
Previous Suggestion ◽  
Chlorobenzoic Acid ◽  
Low Concentrations ◽  
Chlorobenzoic Acids ◽  
Barley Leaves ◽  
Reducing Substances ◽  
Control Samples

The effects of chlorobenzoic acids on respiration, sucrose absorption, and carbohydrate metabolism of etiolated barley leaves were studied. The results showed that respiration was retarded to the same extent irrespective of position of substitution, in the presence of these substances; inhibition was more pronounced at higher concentrations of chlorobenzoic acids. At low concentrations, o-chlorobenzoic acid enhanced sucrose uptake and p-chlorobenzoic inhibited uptake while at higher concentrations, both compounds inhibited sucrose uptake by etiolated barley leaves.Tissue analysis for carbohydrates showed a decrease in all carbohydrate fractions of treated leaves compared to the control samples. Even the sucrose-fed treated samples showed a carbohydrate content similar to that of the samples starving in distilled water in spite of the variable amounts of sugars absorbed by such samples.These observations, together with excretion of some copper-reducing substances that disappeared after clearing, support the previous suggestion (4) that the tissue carbohydrates were mostly transformed to non-sugar substances that might have been excreted as a result of increased permeability in the presence of the chlorobenzoic acids. This suggestion, together with the possibility of deactivation of the respiratory dehydrogenases, may explain the reduced rates of respiration of the treated samples.

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