scholarly journals CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM

1936 ◽  
Vol 20 (1) ◽  
pp. 13-43 ◽  
Author(s):  
W. J. V. Osterhout
Keyword(s):  
Sea Water ◽  
Chemical Compounds ◽  
Monomolecular Layer ◽  
Normal Cells ◽  
Protein Film ◽  
Organic Ions ◽  
Protoplasmic Surface ◽  
Short Latent Period ◽  
Ionic Mobilities ◽  
Cell Changes

In normal cells of Valonia the order of the apparent mobilities of the ions in the non-aqueous protoplasmic surface is K > Cl > Na. After treatment with 0.01 M guaiacol (which does not injure the cell) the order becomes Na > Cl > K. As it does not seem probable that such a reversal could occur with simple ions we may assume provisionally that in the protoplasmic surface we have to do with charged complexes of the type (KXI)+, (KXII)+, where XI and XII are elements or radicals, or with chemical compounds formed in the protoplasm. When 0.01 M guaiacol is added to sea water or to 0.6 M NaCl (both at pH 6.4, where the concentration of the guaiacol ion is negligible) the P.D. of the cell changes (after a short latent period) from about 10 mv. negative to about 28 mv. positive and then slowly returns approximately to its original value (Fig. 1, p. 14). This appears to depend chiefly on changes in the apparent mobilities of organic ions in the protoplasm. The protoplasmic surface is capable of so much change that it does not seem probable that it is a monomolecular layer. It does not behave like a collodion nor a protein film since the apparent mobility of Na+ can increase while that of K+ is decreasing under the influence of guaiacol.

scholarly journals THE KINETICS OF PENETRATION

1937 ◽  
Vol 20 (5) ◽  
pp. 737-766 ◽  
Author(s):  
A. G. Jacques
Keyword(s):  
Sea Water ◽  
Surface Layers ◽  
Marked Contrast ◽  
External Concentration ◽  
Protoplasmic Surface ◽  
Kinetics Of ◽  
External Ph

When 0.1 M NaI is added to the sea water surrounding Valonia iodide appears in the sap, presumably entering as NaI, KI, and HI. As the rate of entrance is not affected by changes in the external pH we conclude that the rate of entrance of HI is negligible in comparison with that of NaI, whose concentration is about 107 times that of HI (the entrance of KI may be neglected for reasons stated). This is in marked contrast with the behavior of sulfide which enters chiefly as H2S. It would seem that permeability to H2S is enormously greater than to Na2S. Similar considerations apply to CO2. In this respect the situation differs greatly from that found with iodide. NaI enters because its activity is greater outside than inside so that no energy need be supplied by the cell. The rate of entrance (i.e. the amount of iodide entering the sap in a given time) is proportional to the external concentration of iodide, or to the external product [N+]o [I-lo, after a certain external concentration of iodide has been reached. At lower concentrations the rate is relatively rapid. The reasons for this are discussed. The rate of passage of NaI through protoplasm is about a million times slower than through water. As the protoplasm is mostly water we may suppose that the delay is due chiefly to the non-aqueous protoplasmic surface layers. It would seem that these must be more than one molecule thick to bring this about. There is no great difference between the rate of entrance in the dark and in the light.

scholarly journals Effect Use of Two Chemical Compounds Sodium Nitrate and Sodium Silicate as Corrosion Inhibitor to Steel Reinforcement

2019 ◽  
Vol 14 (2) ◽  
pp. 123-128
Author(s):  
Sarah Kareem Mohammed
Keyword(s):  
Corrosion Rate ◽  
Sodium Silicate ◽  
Electrolyte Solution ◽  
Sodium Nitrite ◽  
Corrosion Inhibitors ◽  
Sea Water ◽  
Chemical Compounds ◽  
Steel Sample ◽  
Steel Reinforcement ◽  
Corrosion Of Steel

Corrosion of steel reinforcement is one of the biggest problems facing all countries in the world like bridges in the beach area and marine constructions which lead to study these problems and apply some economical solutions. According to the high cost of repair for these constructions, were studied the effect of using kind of chemical compounds sodium nitrite(NaNO2) and sodium silicate(Na2SiO3) as corrosion inhibitors admixture for steel bars that immersed partially in electrolyte solution (water + sodium chloride in 3% conc.) (Approximately similar to the concentration of salt in sea water). The two inhibitors above added each one to the electrolyte solution at concentrations (0.5%, 1% and 2%) for both of them.      The results were  corrosion rate for steel sample that's immersed partially in salt solution was higher than corrosion rate of steel bar that's immersed partially in electrolyte solution with inhibitors  also the two corrosion inhibitors (sodium nitrite and sodium silicate) that added to the electrolyte solution were working successfully to prevent and inhibit the corrosion by using weight loss technique with best percent of 0.5% sodium nitrite ( efficiency 94.1% ) and best percent of 2% sodium silicate ( efficiency 92.5%).

scholarly journals CHANGES OF APPARENT IONIC MOBILITIES IN PROTOPLASM

1938 ◽  
Vol 21 (6) ◽  
pp. 707-720 ◽  
Author(s):  
W. J. V. Osterhout
Keyword(s):  
Organic Substance ◽  
Opposite Effect ◽  
Sea Water ◽  
Inorganic Ions ◽  
Ionic Mobilities ◽  
Combined Action

Lowering the pH of sea water from 8.2 to 6.4 lowers the positive P.D. of Halicystis reversibly (this does not happen with Valonia). Exposure to sea water at pH 6.4 does not affect the apparent mobility of Na+ or of K+ (this agrees with Valonia). Guaiacol makes the P.D. of Halicystis less positive (in Valonia it has the opposite effect). Exposure to guaiacol does not reverse the effect of KCl in Halicystis which in this respect differs from Valonia. The P.D. can be changed from 66 mv. positive to 23 mv. negative by the combined action of KCl and guaiacol. Exposure to guaiacol affects Halicystis and Valonia similarly in respect to their behavior with dilute sea water. Normally the dilute sea water makes the P.D. more negative but after sufficient exposure to guaiacol dilute sea water either produces no change in P.D. or makes it more positive. In the latter case we may assume that the apparent mobility of Na+ has become greater than that of Cl- as the result of the action of guaiacol. (Normally the apparent mobility of Cl- is greater than that of Na+.) In Halicystis, as in Valonia and in Nitella, an organic substance can greatly change the apparent mobilities of certain inorganic ions (K+ or Na+).

scholarly journals On the Culture of the Plankton Diatom Thalassiosira grauida Cleve, in Artificial Sea-water

1914 ◽  
Vol 10 (3) ◽  
pp. 417-439 ◽  
Author(s):  
E. J. Allen
Keyword(s):  
Organic Compound ◽  
Culture Medium ◽  
Sea Water ◽  
Chemical Compounds ◽  
Distilled Water ◽  
Artificial Medium ◽  
Plant Life ◽  
Specific Substance ◽  
Vigorous Growth ◽  
Better Than

1. Attempts to obtain good cultures of Thalassiosira gravida in a purely artificial medium, made by dissolving in doubly distilled water Kahlbaum's pure chemicals in the proportions in which the salts occur in sea-water, adding nitrates, phosphates and iron according to Miquel's method and sterilizing the medium, have not succeeded.If, however, a small percentage of natural sea-water (less than 1 per cent will produce a result) be added to the artificial medium and the whole sterilized excellent cultures are obtained, which are often better than any which have been got when natural sea-water forms the foundation of the culture medium.The result appears to be due to some specific substance present in minute quantity in the natural sea-water which is essential to the vigorous growth of the diatoms. The nature of this substance it has not been possible to determine, but some evidence seems to suggest that it is a somewhat stable organic compound.Provided the 1 per cent of natural sea-water is added, the various constituents of the artificial sea-water forming the basis of the culture medium can be varied in amount within wide limits. The salinity of the medium can also be considerably altered without serious detriment to the cultures.The experiments recorded are of interest as furnishing another instance of the importance in food substances of minute traces of particular chemical compounds. They may also eventually throw light upon the nature of the conditions in the sea which are specially favourable to the production of plant life and therefore also of the animal life which that plant life sustains.

scholarly journals The Problem of Plastic Waste and Microplastics in the Seas and Oceans: Impact on Marine Organisms

2019 ◽  
Vol 77 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Antonia Kurtela ◽  
Nenad Antolović
Keyword(s):  
Sea Water ◽  
Plastic Material ◽  
Chemical Compounds ◽  
Marine Organisms ◽  
Plastic Waste ◽  
Pathogenic Microorganisms ◽  
The Public ◽  
Plastic Materials ◽  
Pass Through ◽  
State Organizations

Abstract A global problem of today is the large amount of waste in the seas and oceans, primarily plastic waste. It is estimated that every year 1.25 to 2.41 million tons of plastic material is being carried by rivers into the seas and oceans. Waste is a major problem for marine organisms, causing entanglement, choking, strangulation, malnutrition and death. In 1972 the problems caused by microplastics, particles smaller than 5 mm, were first observed. Such particles bind pathogenic microorganisms on to their surface. Increasing quantities of microplastics have been found in the stomachs of fish, and also in shellfish that feed by filtering sea water. Ingested by marine organisms, such plastics may eventually pass through the food web and can end up ingested by humans. In addition, plastic releases chemical compounds whose effect on marine organisms and humans has still not been studied. Many international and state organizations offer solutions through recycling plastic waste, as well as reducing the production of plastic materials and informing the public about the problem.

scholarly journals THE EFFECT OF ORGANIC IONS ON THE MEMBRANE POTENTIAL OF NERVES

1937 ◽  
Vol 20 (4) ◽  
pp. 519-541 ◽  
Author(s):  
W. Wilbrandt
Keyword(s):  
Membrane Potential ◽  
Sciatic Nerve ◽  
Osmotic Pressure ◽  
Sea Water ◽  
Porous Membrane ◽  
Resting Potential ◽  
Spider Crab ◽  
Nerve Membrane ◽  
Myelinated Nerve ◽  
Organic Ions

1. The effect of osmotic pressure on the nerve resting potential of frog sciatic nerve is in accordance with the assumption of a membrane potential; increased osmotic pressure raises, decreased osmotic pressure lowers the potential. 2. The potential of crab nerves is affected by organic and inorganic cations in the approximate series: Rb > K = diamylamine > dibutylamine > guanidine > tetraethylamine > diethylamine = dimethylamine > dipropylamine > tetramethylamine = choline = Na = Li. 3. The response of the potential to the series of dialkylamines (first decrease, then increase of response ascending in the series) is best understood by the assumption that the nerve membrane is a porous structure. 4. With respect to these salts as well as to other organic cations the dried collodion membrane as a model of a porous membrane shows a striking parallelism to the nerve membrane. 5. Both inorganic and organic anions (NO3, SCN, acetate, propionate, butyrate, lactate, pyruvate) have a definite, if slight, effect in raising the potential of crab nerves. This effect of anions indicates that the nerve membrane is not completely anion impermeable. 6. The effect of organic ions is, with certain restrictions, reversible. Its possible relation to the resting potential and to the after potentials of the electrical disturbance is discussed. 7. The response of the myelinated sciatic nerve of the frog and of the non-myelinated nerve of the spider crab show considerable agreement. There are some definite differences which are, however, not necessarily due to differences of the cell membranes involved, but may be ascribed to the difference of ionic conditions in Ringer and sea water.

scholarly journals STABILIZATION OF SPIDER CRAB NERVE MEMBRANES BY ALKALINE EARTHS, AS MANIFESTED IN RESTING POTENTIAL MEASUREMENTS

1940 ◽  
Vol 23 (3) ◽  
pp. 343-364 ◽  
Author(s):  
Rita Guttman
Keyword(s):  
Chloral Hydrate ◽  
Sea Water ◽  
Resting Potential ◽  
Spider Crab ◽  
Sulfate Concentration ◽  
Water Solutions ◽  
Organic Ions ◽  
Hypertonic Solutions ◽  
Alkaline Earths

1. The alkaline earths, Ba, Sr, Ca, and Mg, in isotonic solutions of their chlorides, have, in general, no effect upon the resting potential of non-medullated spider crab nerve. 2. Ba, Sr, and Ca can, however, prevent the depressing action of K upon the resting potential. The order of effectiveness of these ions in this regard is the following: Ba > Sr > Ca. 3. Ba, Sr, Ca, and Mg oppose the depressing action of veratrine sulfate upon the resting potential. The order of effectiveness is Ba > Sr > Ca > Mg. The relation between drop in potential caused by veratrine sulfate and the logarithm of the veratrine sulfate concentration is a linear one. 4. The action of various other organic ions and molecules which depress the resting potential: saponin, amyl urethane, chloral hydrate, and Na salicylate is neutralized by Ba. 5. Hypertonic sea water solutions do not affect the resting potential. Also, preliminary experiments indicate that the nerves do not shrink in hypertonic solutions although they swell in hypotonic sea water. 6. The alkaline earths depress excitability reversibly. The various organic agents which depress the resting potential also depress excitability, in most cases, reversibly, but the concentrations necessary to depress excitability are much smaller than those necessary to depress the resting potential. 7. The relation of these findings to theories put forward as possible explanations of resting potential phenomena is considered.

scholarly journals THE MECHANISM OF ACCUMULATION IN LIVING CELLS

1952 ◽  
Vol 35 (4) ◽  
pp. 579-594 ◽  
Author(s):  
W. J. V. Osterhout
Keyword(s):  
Osmotic Pressure ◽  
Outer Surface ◽  
Organic Molecules ◽  
Sea Water ◽  
Relative Rate ◽  
Point Of View ◽  
External Concentration ◽  
Protoplasmic Surface ◽  
A Cell ◽  
Outer Protoplasmic Surface

When a compound enters a living cell until its activity becomes greater inside than outside, it may be said to accumulate. Since it moves from a region where its activity is relatively low to a region where its activity is relatively high, it is evident that work must be done to bring this about. The following explanation is suggested to account for accumulation. The protoplasmic surface is covered with a non-aqueous layer which is permeable to molecules but almost impermeable to ions. Hence free ions cannot enter except in very small numbers. The experiments indicate that ions combine at the outer surface with organic molecules (carrier molecules) and are thus able to enter freely. If upon reaching the aqueous protoplasm these molecules are decomposed or altered so as to set the ions free, the ions must be trapped since they cannot pass out except in very small numbers. If we adopt this point of view we can suggest answers to some important questions. Among these are the following: 1. Why accumulation is confined to electrolytes. This is evident since only ions will be trapped. 2. Why ions appear to penetrate against a gradient. Actually there is no such penetration since the ions enter in combination with molecules. The energy needed to raise the activity of entering compounds is furnished by the reactions involved in the process of accumulation. 3. Why, in absence of injury, ions do not come out when the cell is placed in distilled water. Presumably the outgoing ions will combine at the outer surface with carrier molecules and then move inward in the same way as ions coming from without. 4. Why the relative rate of penetration falls off as the external concentration increases. This is because the entrance of ions is limited by the number of carrier molecules but no such limitation exists when ions move outward since they can do so without combining with carrier molecules. 5. Why accumulation is promoted by constructive metabolism which is needed to build up the organic molecules and by destructive metabolism which brings about their decomposition. 6. Why measuring the mobilities of ions in the outer protoplasmic surface does not enable us to predict the relative rate of entrance of ions. We find for example in Nitella that K+ has a much higher mobility than Na+ but the accumulation of these ions does not differ greatly. This is to be expected if they enter by combining with molecules at the surface. Only if K+ is able to combine preferentially will it accumulate preferentially. 7. Why ions may come out in anoxia and at low temperatures. If these conditions depress the formation of carrier molecules and their decomposition in the protoplasm, the balance between intake and outgo of ions will be disturbed and relatively more may come out. 8. Why the excess of internal over external osmotic pressure is less in sea water than in fresh water. As the external concentration of ions increases the rate of intake does not increase in direct proportion since the number of carrier molecules does not increase and this slows down the relative rate of intake of ions. But it does not slow down the rate of exit of ions since they need not combine with carrier molecules in order to pass out. Hence the excess of ions inside will be relatively less as the concentration of external ions increases. 9. How water is pumped from solutions of higher to solutions of lower osmotic pressure. If metabolism and consequently accumulation is higher at one end of a cell than at the other, the internal osmotic pressure will be higher at the more active end and this makes it possible for the cell to pump water from solutions of higher osmotic pressure at the more active end to solutions of lower osmotic pressure at the less active, as shown experimentally for Nitella. This might help to explain the action of kidney cells and the production of root pressure in plants.

scholarly journals ABNORMAL PROTOPLASMIC PATTERNS AND DEATH IN SLIGHTLY HYPERTONIC SOLUTIONS

1948 ◽  
Vol 31 (3) ◽  
pp. 291-300 ◽  
Author(s):  
W. J. V. Osterhout
Keyword(s):  
Outer Surface ◽  
Sea Water ◽  
External Solution ◽  
Mechanical Action ◽  
Characteristic Pattern ◽  
Hypertonic Solutions ◽  
Protoplasmic Surface ◽  
Made In

Some interesting properties of protoplasm are revealed when slightly hypertonic solutions of sugars or of electrolytes are applied to Nitella. The chloroplasts contract and the space between them increases and forms a characteristic pattern consisting of clear areas extending lengthwise along the cell and tapering off at both ends. The development of these areas is irreversible from the start. If the cell is returned to water after plasmolysis begins these areas continue to enlarge in much the same fashion as when no change is made in the external solution. The cell soon dies whether returned to water or left in the plasmolyzing solution. Similar results are obtained with other sugars, with NaCl, CaCl2, and sea water. Similar reactions are also brought about by strong ingoing or outgoing currents of water. This suggests that mechanical action may be chiefly responsible for the result and this idea is in harmony with other facts. It seems possible that the retraction of the protoplasm from the cellulose wall may disturb the delicate non-aqueous film which covers the outer surface of the protoplasm and thus produce injury. Such an effect might take place even without visible retraction if the injury occurred in protoplasmic projections extending into the cellulose wall. A study of this behavior may throw light on the nature of the protoplasmic surface and on the properties of protoplasmic gels as well as on the process of death. An understanding of the mechanism involved may help to explain the action of hypertonic solutions in other cases as, for example, in the artificial parthenogenesis of marine eggs.

scholarly journals DELAYED POTASSIUM EFFECT IN NITELLA

1938 ◽  
Vol 22 (1) ◽  
pp. 107-113 ◽  
Author(s):  
S. E. Hill ◽  
W. J. V. Osterhout
Keyword(s):  
Organic Substance ◽  
Normal Cells ◽  
Protoplasmic Surface ◽  
Potassium Effect ◽  
Time Required

In normal cells of Nitella replacement of NaCl by KCl makes the P.D. much less positive: this is called the potassium effect. Cells which have lost the potassium effect usually show little or no change of P.D. when NaCl is replaced by KCl but an occasional cell responds after a delay. It seems possible that the delay may be largely due to the time required for potassium to combine with an organic substance, thus forming a compound which sensitizes the protoplasmic surface to the action of potassium.

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