50 research outputs found
Etude comparative des vitesses de synthase des protéines et de renouvellement de l'acide ribonucléique
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Grana formation and synthesis of chloroplastic proteins induced by light in portions of etiolated leaves
A comparison between plastids from etiolated and green leaves with the electron microscope shows a radically different structure in these two types of particles. The leucoplasts do not contain grana; they show a finely granular structure. They are smaller than chloroplasts. By simply exposing to light fragments of etiolated leaves, the transformation of leucoplasts into normal characteristic chloroplasts is induced within a few hours. This transformation is accompanied by a significant net synthesis of chloroplastic proteins that occur at the expense of free amino compounds of which etiolated leaves contain a considerable reserve. © 1954.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Multiplicity of the amino acid permeases in Saccharomyces cerevisiae. II. Evidence for a specific lysine-transporting system
1. 1. The initial velocity of entrance of L-[14C]lysine into yeast cells appears, according to a Lineweaver-Burk plot, to be dependent on two functions. Evidence is presented showing that lysine enters the cell by two distinct systems. 2. 2. One of these systems is the arginine permease: it has been lost in the arg-p1 mutants (canavanine-resistant, arginine permease-less) and is specifically and competitively inhibited by L-arginine with a Ki of 10-5 M identical with the Km of arginine for its permease. Its apparent affinity constanct for lysine is about 2·10-4 M. 3. 3. The other lysine-uptake system has a higher affinity for lysine (Km, 2.5·10-5 M). IT is highly specific for lysine, as shown by competition experiments and by the fact that the loss of its activity by mutation (lys-P1) affects lysine uptake exclusively. 4. 4. It is concluded: (a) that a very specific lysine permease distinct and independent of the arginine permease exists in yeast; (b) that lysine may enter the cell by means of the arginine permease, while arginine cannot use the lysine permease. © 1966.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
The mass induction of white strains in Euglena as influenced by the physiological conditions
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Chapter 7 Amino acid transporters in yeast: structure, function and regulation
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Physiology and Cytology of Chloroplast Formation and "Loss" in Euglena
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Étude de la vitesse de renouvellement de l'acide ribonucléique dans des cellules effectuant une synthèse de protéines rapide et directement mesurable. II. L'oviducte de poule pondeuse
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Synthèse des protéines et vitesse de renouvellement du phosphore de l'acide ribonucléique
A comparative study of the rate of protein sythesis and the rate of renewal of the RNA P in bird feather buds, laying hen's oviduct and mouse pancreas shows that, although these three organs synthesize proteins at a very high rate, the first tissue seems to present a parallel renewal of RNA P, whereas in the oviduct and the pancreas (even when, in the latter, synthesis is increased by pilocarpin injection) this rate is very low, considerably lower than the rate of protein synthesis. Thus, there does not exist a necessary relationship between the rate of renewal of RNA P and the rate of protein synthesis. These results are not in favour of the hypothesis which ascribes to RNA a metabolic role in protein synthesis, but, on the contrary, supports the idea that, if RNA does play a role in protein synthesis, as numerous experimental results seem to indicate, its action resembles more that of a model, a pattern or a catalytic agent. © 1953.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Action de la streptomycine sur la formation des chloroplastes
A study of the acction of Sm on the formation of chloroplasts by Hordeum vulgare: 1. confirmed the idea that Sm inhibits not only the synthesis of the chlorophylls, but also that of the chloroplasts themselves; 2. shows that Sm has a specific action on the development of the chloroplasts, attaining several chloroplastic constituents, whereas others are not touched (respiratory system for example). Barely seedlings which had formed white leaves as a consequence of the action of Sm are still able to produce normal green leaves when Sm is removed. Hence, Sm does not alter the hereditary properties of the higher plant studied, by provoking the mutation of nuclear genes nor by eliminating cytoplasmic units possessing genetic continuity. Sm inhibits the growth and the differentiation of proplastids into chloroplasts without preventing their multiplication. © 1995.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Étude de la vitesse de renouvellement de l'acide ribonucléique dans des cellules effectuant une synthèse de protéines rapide et directement mesurable
SCOPUS: ar.jinfo:eu-repo/semantics/publishe