Reducing activity and the formation of base in the coralline algae: an electrochemical model

1979 ◽  
Vol 59 (2) ◽  
pp. 455-477 ◽  
Author(s):  
P. S. B. Digby
Keyword(s):  
Carbon Dioxide ◽  
Outer Surface ◽  
Sea Water ◽  
Carbonic Anhydrase Activity ◽  
Coralline Algae ◽  
Platinum Foil ◽  
Surrounding Water ◽  
Electrode Potentials ◽  
Acid And Base ◽  
Reducing Activity

SUMMARY AND CONCLUSIONSIn the process of calcification in the coralline algae, Clathromorphum and Corallina, the energy is derived from photosynthesis; the outer surface evolves carbon dioxide while calcium carbonate is deposited between the algal filaments. Evidence suggests that calcification may be brought about essentially by separation of acid and base followed by preferential removal of an acid component in the form of carbon dioxide.These algae show strong oxidase, catalase and carbonic anhydrase activity, consistent with the processes postulated. The calcified algal thallus is normally reducing. Platinum electrode potentials, Eh, measured on and immediately below the outer surface of fresh and healthy Clathromorphum crust following abrasion ranged from 50 to 100 mV, some 150–370 mV negative to that of the surrounding water at the time. These potentials in the alga were most reducing after the material had been exposed to strong sunlight. Eh potentials, measured by electrodes of platinum foil attached to the outer surface of Clathromorphum in such a way as to shield it from light and from gaseous exchange from the sea water, reached values between 113 and -182 mV, or up to 480 mV negative to the Eh of the surrounding sea water.Oxidation of crude suspensions of crushed fresh material showing reducing activity resulted in the production of base by removal of hydrogen ions. The amount of base so formed was greater when suspensions were first incubated out of contact with air for periods of up to several days, reducing conditions being enhanced by respiration of the alga alone or in conjunction with bacterial growth.

Reducing Activity and the Formation of Base in the Shore Crab, Carcinus Maenas

1985 ◽  
Vol 65 (2) ◽  
pp. 505-530 ◽  
Author(s):  
Peter S. B. Digby
Keyword(s):  
Outer Surface ◽  
Biological Material ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Water Salinity ◽  
Shore Crab ◽  
Calcareous Deposits ◽  
Reducing Activity ◽  
Diffusion Potentials ◽  
Active Processes

Crustacean cuticle consists essentially of chitin impregnated and coated with protein which is tanned with quinone (Dennell, 1947a). The outer surface is most heavily tanned, and the cuticle is further strengthened by calcification. The various theories as to the mechanism of calcification in crustacean and other biological material have been reviewed briefly by Digby (1967). Most appear unsatisfactory for various reasons, and evidence was outlined that calcification might arise from the formation of base by processes which are essentially electrochemical in origin. The quinone-tanned protein of the cuticle is electrically semiconducting and supports electrode action in suitable gradients of potential (Digby, 1965), and small potential differences may arise by diffusion or by active processes. Thus the deposition of calcareous salts might arise partly at least by action comparable to that which takes place at a metallic cathode. In support of this, the position of the initial calcareous deposits in Carcinus maenas (L.) was found to change with the gradient of sea-water salinity in the manner expected if some control were exercised by diffusion potentials, acting across a thin semiconducting layer to generate small changes of pH (Digby, 1968).

scholarly journals CAN CARBON DIOXIDE IN SEA WATER BE DIRECTLY DETERMINED BY TITRATION?

1916 ◽  
Vol 24 (1) ◽  
pp. 31-35
Author(s):  
Sergius Morgulis ◽  
Everett W. Fuller
Keyword(s):  
Carbon Dioxide ◽  
Sea Water

Carbon dioxide storage in Dead Sea water

2021 ◽  
Author(s):  
Mohammad Al-Harahsheh ◽  
Raghad Al-Khatib ◽  
Aiman Al-Rawajfeh
Keyword(s):  
Carbon Dioxide ◽  
Sea Water ◽  
Dead Sea ◽  
Carbon Dioxide Storage

Holding of Atlantic Mackerel (Scomber scombrus) in Refrigerated Sea Water

1977 ◽  
Vol 34 (3) ◽  
pp. 439-443 ◽  
Author(s):  
D. W. Lemon ◽  
L. W. Regier
Keyword(s):  
Carbon Dioxide ◽  
Sea Water ◽  
Fish Muscle ◽  
Sodium Content ◽  
Oxidative Rancidity ◽  
Dissolved Carbon ◽  
Atlantic Mackerel ◽  
Scomber Scombrus ◽  
Dissolved Carbon Dioxide ◽  
Lower Temperature

Refrigerated sea water proved to be an improved method of holding Atlantic mackerel (Scomber scombrus). The uniform lower temperature and reduction in available oxygen retarded the development of oxidative rancidity. Textural deterioration was also retarded. The sodium uptake from and the potassium loss to the sea water was not excessive, and taste panelists could not consistently identify samples with elevated sodium content. The addition of carbon dioxide to the RSW did not regularly affect the level of spoilage as monitored by the measurement of trimethylamine. The values, however, were low for all holding systems, even after 9 days. The presence of dissolved carbon dioxide in the fish muscle made the fish unacceptable for canning.

CARBONIC ANHYDRASE IN THE PREMATURE

PEDIATRICS ◽  
1968 ◽  
Vol 42 (3) ◽  
pp. 429-436
Author(s):  
E. Poblete ◽  
D. W. Thibeault ◽  
P. A. M. Auld
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Premature Infants ◽  
Carbonic Anhydrase Activity ◽  
Full Term ◽  
Term Infants ◽  
Low Levels

Carbonic anhydrase activity was measured in the blood of premature and full-term infants to determine if the arterial-alveolar carbon dioxide gradient was related to low levels of carbonic anhydrase. The time at which levels in these infants approached the adult was studied as well. The study demonstrates that CO2 gradients do not correlate with blood carbonic anhydrase activity, and minimal or no activity can be associated with a small gradient. An increase in the carbonic anhydrase activity-produced by transfusion did not significantly change the CO2 gradient. Premature infants approach adult levels of activity in 6 to 7 months.

The Effect of Salinity Changes on the Water Content and Respiration of Marine Invertebrates

1931 ◽  
Vol 8 (3) ◽  
pp. 211-227
Author(s):  
L. C. BEADLE
Keyword(s):  
Respiratory Rate ◽  
Marine Invertebrates ◽  
Sea Water ◽  
Oxygen Intake ◽  
Anaerobic Conditions ◽  
Marine Animals ◽  
Surrounding Water ◽  
Low Salinity ◽  
Initial Difference ◽  
Good Support

1. Schlieper's theory of the function of increased oxygen intake by "homoiosmotic" marine invertebrates in dilute sea water in maintaining their body fluids hypertonic to the surrounding water is discussed, and objections are brought forward to the methods used in the experiments on which his conclusions were based. 2. By periodic weighings, and measurements of respiratory rate (under narcotic) by Barcroft manometers, it was found that the weight of N. diversicolor, on transference to water of low salinity, at first increases and then falls, and that the respiratory rate is at first increased and later tends to decrease. 3. With N. cultrifera the weight increases to a higher value and does not sub sequently fall, and the respiratory rate is also increased but to a lesser extent than with N. diversicolor. 4. These differences in the amount of increase in respiratory rate are more marked in water containing only 16.6 per cent, sea water than in water containing 25 per cent, sea water. 5. N. diversicolor maintains its activity while N. cultifera becomes practically inert in dilute water. The latter does not actually die in 25 per cent, sea water after 100 hours, but dies in 16.6 per cent, sea water after about 50 hours. 6. Exposure to M/1000 KCN or to anaerobic conditions in dilute water tends to break down the mechanism by which the free osmotic inflow of water in N. diversicolor is prevented, and the weight curves under these conditions approach the N. cultrifera form. 7. The respiratory rate of G. ulvae increases progressively with dilution of the sea water, and is roughly proportional to the initial difference of osmotic pressure inside and outside the animal. 8. The swelling of Gunda in dilute water is due to swelling of the gut cells, which become much vacuolated. The other tissues appear unaltered. 9. M/1000 KCN or anaerobic conditions cause a greater amount of swelling in Gunda in a given salinity than normally occurs. 10. These experiments seem to give reasonably good support to Schlieper's hypothesis. 11. The mechanism responsible for this "osmotic resistance" in N. diversicolor must be of a somewhat different nature from that in G. ulvae. 12. A rigid distinction between "homoiosmotic" and "poikilosmotic" marine animals cannot be supported.

The Respiratory Metabolism of Dendrostomum cymodoceae Edmonds (Sipunculoidea)

1957 ◽  
Vol 8 (1) ◽  
pp. 55 ◽  
Author(s):  
SJ Edmonds
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Dissolved Oxygen ◽  
Blood Volume ◽  
Sea Water ◽  
Respiratory Metabolism ◽  
Anaerobic Conditions ◽  
Paraffin Oil ◽  
End Products ◽  
Wet Weight

The consumption of oxygen of Dendrostomum cymodoceae at 22'C in aerated sea-water varied from 4-5-5.5 μl/g (wet weight)/hr for adults to 20-31 μ/g/hr for juveniles. The production of carbon dioxide was 13-17 μ/g/hr (juveniles) and the R.Q. varied from 0.55 to 0.67 (juveniles). The rate of consunlption of oxygen decreased as the tension of the dissolved oxygen decreased. The oxygen combined with the pigment of the blood was 2.1 vols. of oxygen per 100 vols. of blood and the ratio of blood volume (ml) to total weight (g) of the animal was 0.47. D. cymodoceae was able to live under anaerobic conditions in sea-water for as long as 5 days and in paraffin oil for 4 days. The haemerythrin in the blood of animals kept under oil was found to be reduced after about 6 hr. Lactic acid was identified as one of the end-products of anaerobiosis. The concentration of lactic acid in the blood of animals living under anaerobic conditions increased after 60 hr from 7-12 to 46-61 μg/ml of blood. The ability to revert to anaerobiosis may have survival value for the species.

Determination of carbon dioxide and titratable base in sea water

1932 ◽  
Vol 4 (3) ◽  
pp. 309-313 ◽  
Author(s):  
David M. Greenberg ◽  
Erik G. Moberg ◽  
Esther C. Allen
Keyword(s):  
Carbon Dioxide ◽  
Sea Water
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