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141.
Seed Proteins of Peas in Relation to Nitrogen Fixation 总被引:2,自引:0,他引:2
The influence of the source of nitrogen on the amount and compositionof the seed protein has been examined. The plants were grownin sterile compost and those that had received their nitrogenas ammonium nitrate compared with those in which nitrogen fixationoccurred in the root nodules. The absence of nodules in theformer and the presence of nitrogen fixation in the latter wasconfirmed. The source of nitrogen did not affect the amountsof extractable seed protein, the proportions of the differentfractions or their composition. 相似文献
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JOHNSTON CD 《Archives of biochemistry and biophysics》1951,31(3):375-382
DDT and several of its related compounds were found to be inhibitory to rat heart succinoxidase at concentrations of from 10?4 to 10?5M, the degree of inhibition being about 70–90% at the higher concentrations. This inhibition could also be shown for cytochrome oxidase, but not for succinic dehydrogenase. The inhibition was demonstrable when the insecticide or its derivatives were added to the enzyme system as alcoholic solutions. Cholesterol at the same concentrations did not inhibit succinoxidase.When DDT was present in an oil emulsion, only a slight inhibition could be shown toward the succinoxidase system, even though the concentration in the emulsion was 10 times that of the highest level in alcohol.DDA, the acetic acid derivative of DDT, and a known metabolite thereof, was much less inhibitory toward the succinoxidase and cytochrome oxidase systems, even at 5 × 10?4M. 相似文献
144.
SYNOPSIS. Haemogregarina bigemina was found in all Blennius pholis which exceeded 5.0 cm in length, but in none measuring less than 3.5 cm. No exoerythrocytic development was recorded. The first B. pholis eggs hatched in May while the first patent infections of H. bigemina occurred from September onward in metamorphosed fish. Consequently, if the life cycle of H. bigemina includes a vector, that organism is active between May and September at least. Circumstantial evidence indicates that the hematophagous isopod, Gnathia maxillaris and not leeches, could be a vector of H. bigemina. Developmental stages of sporozoa were found in a small number of the isopods which had fed on infected B. pholis but the parasites could not be identified as H. bigemina with certainty. Subcellular organization, typical of sporozoa, was recorded by electron microscopy of H. bigemina. 相似文献
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The utilization of bicarbonate ions by the macroalga Ascophyllum nodosum (L.) Le Jolis 总被引:4,自引:2,他引:2
Abstract A comparison of some of the methods used to determine whether aquatic plants have the ability to utilize bicarbonate ions as a source of inorganic carbon for photosynthesis has been applied to the intertidal macroalga Ascophyllum nodosum. These include: observing photosynthesis at a high pH (below the alga's CO2 compensation point), pH compensation point determinations, comparing the photosynthetic characteristics at low pH (5.20) and at high pH (7.95), estimating the maximal rates at which CO2 can diffuse through the unstirred layer and the rate at which CO2 can be produced from bicarbonate dehydration in the unstirred layer. All indicated that Ascophyllum nodosum can use bicarbonate ions for photosynthesis, though some were not always consistent. Calculating the total inorganic carbon concentration from pH measurements and acidification CO2 determinations revealed that the assumption that the alkalinity remains constant during pH drift experiments is not always valid. 相似文献