Modern methods of plant analysis
01 Jan 1964-
About: The article was published on 1964-01-01 and is currently open access. It has received 1991 citations till now.
Citations
More filters
TL;DR: A method of separating amylose and amylopectin is based on proteolysis of the precipitated concanavalin A-amylophectin complex as discussed by the authors.
32 citations
TL;DR: In this article, the first 8 years of new plantations ofPopulus deltoidesBartr. raised after the clear-felling of natural mixed broad-leaved forests in the subtropical zone of the Kumaun Himalaya were compared with similar measurements under the original forest cover.
32 citations
TL;DR: It is demonstrated that seeds of C. cathartica were high in protein, essential amino acids and low in saturated fatty acids and anti-nutritional factors.
32 citations
TL;DR: In this paper, Yucca saponin added to broiler diets did not significantly increase body weights; however, it improved feed efficiency of broilers when fed with 121 ppm of monensin.
32 citations
TL;DR: A nitrogen-deficient state for algal cells induced by strong light, low temperature or a limited supply of nitrogen leads to a modification of the physicochemical state of in vivo fu Coxanthin, so that the excitation energy of fucoxanthin is less efficiently transferred to chlorophyll a.
Abstract: Variations in the photosynthetic activity under monochromatic light was studied in Phaeodactulum tricornutum grown under various culture conditions, with special reference to the composition of photosynthetic pigments. Photosynthetic activity, under light-limiting conditions, was reduced when the cells were grown under strong light. The reduction was more extensive in activity resulting from fucoxanthin-excitation than in that from chlorophyll a-excitation. The diminution in activity for fucoxanthin-excited photosynthesis did not correlate with variations in the pigment content. A similar diminution was observed with chlorophyll a fluorescence upon excitation of fucoxanthin. The change was accelerated by lowering the culture temperature, or limiting the supply of nitrogen source. The results were interpreted in terms of a nitrogen-deficient state for algal cells induced by strong light, low temperature or a limited supply of nitrogen. This leads to a modification of the physicochemical state of in vivo fucoxanthin, so that the excitation energy of fucoxanthin is less efficiently transferred to chlorophyll a. The significance of the phenomenon in the oceanic primary production is discussed.
32 citations
References
More filters
01 Jan 1963
TL;DR: In this article, a physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln.
Abstract: Kann ein physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), so besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln. Hierzu gehoren die Bestimmung der Reaktions- und Substratspezifitat sowie die Ermittlung der Bedingungen, unter denen eine optimale Wirkung des Enzyms gegeben ist. Wesentlich zur Charakterisierung ist ferner die Untersuchung der Stabilitat des Enzyms und dabei insbesondere die Feststellung, ob es sich um ein Ferment handelt, das zur vollen Aktivitat dialysable Cofaktoren benotigt. Falls diese Frage bejaht wird, ist auch die Bestimmung der unerlaslichen Cofaktoren anzuschliesen. Uberdies bietet auch der Nachweis der Lokalisation des Enzyms in der Zelle (oder im Zellverband) eine entscheidende Moglichkeit zur Charakterisierung des Fermentes. Hinzu kommt schlieslich noch die Untersuchung der Wirkung einzelner Inhibitoren1 auf das Enzym, die zu weitgehender Klarung des Reaktionsmechanismus beitragen kann und eine Abgrenzung der Eigenschaften des untersuchten Fermentes gegenuber ahnlichen Enzymen erlaubt.
2 citations
01 Jan 1962
TL;DR: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins and rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
Abstract: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins. Generally speaking denaturation can be defined as a process or sequence of processes in which the spatial arrangement of the polypeptide chains within the molecule is changed from that typical of the native protein to a more disordered arrangement (Kauzmann 1959). The terms “configuration”, “conformation” and “state of folding” are widely used for spatial arrangement. It is probably best to follow the suggestion of Blout (1960) and restrict the use of “configuration” to its original sense, i.e. the spatial arrangement around an asymmetric carbon atom, and to use “conformation” for the shape of the molecule in its entirety. The properties discussed in the previous Chapter i.e., viscosity, diffusion, sedimentation, and light scattering — can all furnish information on the overall shape of proteins or other macromolecules and changes in this shape with environment. Thus Doty, Bradbury and Holtzer (1956) were able to show using these methods, together with streaming birefringence, that poly-γ-benzyl-L-glutamate could exist in two conformations, the α-helix and the solvated randomly coiled form, depending on the solvent. The change from α-helix to random coil was accompanied by marked changes in the optical rotatory properties of the polypeptides. It is to be expected that an α-helical structure should contribute to the rotatory power of a polypeptide since helices are asymmetric and not superimposable on their mirror images. The work on polypeptides has shown that rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
1 citations