Photoregulation
Mostrando 1-12 de 35 artigos, teses e dissertações.
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1. Alcalóides de Psychotria : fotorregulação e propriedades antioxidantes e antimutagênicas
Espécies de Psychotria encontradas no sul do Brasil produzem alcalóides do tipo monoterpeno indólicos, alguns deles com interessantes atividades biológicas e oriundos de novas rotas biossintéticas. P. leiocarpa Cham. & Schlecht. acumula N, b-D-glicopiranosilvincosamida (GPV), o primeiro alcalóide N-glicosilado desta classe a ser descrito. O extrato con
Publicado em: 2007
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2. Effect of light on several metabolites of carbohydrate metabolism in Phycomyces blakesleeanus.
The concentrations of all metabolites studied, except fructose 1,6-bisphosphate from wild-type Phycomyces blakesleeanus, were light dependent. This photoregulation appears to be independent of the mad gene product(s) and also independent of carotene biosynthesis regulation. However, the photoregulation of glyceraldehyde 3-phosphate, 2-phosphoglycerate, and p
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3. Photoregulation of Biological Activity By Photocromic Reagents, II. Inhibitors of Acetylcholinesterase
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4. Photoregulation of Biological Activity by Photochromic Reagents, IV. A Model for Diurnal Variation of Enzymic Activity*
Levels of acetylcholinesterase activity can be made to vary in response to the presence or absence of sunlight in a system that can be considered as a model for photoperiodic processes found in nature. The enzyme is rendered photosensitive by the presence of a photochromic inhibitor, N-p-phenylazophenylcarbamyl choline, which changes from a trans to a cis is
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5. Cryptochrome, Phytochrome, and the Photoregulation of Anthocyanin Production under Blue Light
The principle of equivalent light action predicts that two light treatments (wavelengths ^λ1 and λ2) producing the same Pfr/P ratio (φλ1 = φλ2) and the same rate of phytochrome photoconversion (kλ1 = kλ2) are perceived by phytochrome as being the same and should produce the same effect. The results of experiments based on the principle of equivalent
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6. PHOTOREGULATION OF BIOLOGICAL ACTIVITY BY PHOTOCHROMIC REAGENTS, III. PHOTOREGULATION OF BIOELECTRICITY BY ACETYLCHOLINE RECEPTOR INHIBITORS*
The photochromic compounds N-p-phenylazophenyl-N-phenylcarbamylcholine chloride and p-phenylazophenyltrimethylammonium chloride inhibit the carbamylcholine-produced depolarization of the excitable membrane of the monocellular electroplax preparation of Electrophorus. The trans isomer of each predominates in the light of a photoflood (420 mμ) lamp; they are
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7. Photoactivation of Urocanase in Pseudomonas putida: Possible Role in Photoregulation of Histidine Metabolism
Irradiation by near-ultraviolet light of cells or extracts of Pseudomonas putida increased the urocanase activity. Irradiated cells exhibited enhanced catabolic activity on histidine and urocanate.
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8. Photoregulation of Fructose and Glucose Respiration in the Intact Chloroplasts of Chlamydomonas reinhardtii F-60 and Spinach.
The photoregulation of chloroplastic respiration was studied by monitoring in darkness and in light the release of 14CO2 from whole chloroplasts of Chlamydomonas reinhardtii F-60 and spinach (Spinacia oleracea L.) supplied externally with [14C] glucose and [14C]-fructose, respectively. CO2 release was inhibited more than 90% in both chloroplasts by a light i
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9. Molecular characterization of phycobilisome regulatory mutants of Fremyella diplosiphon.
Three classes of pigment mutants were generated in Fremyella diplosiphon in the course of electroporation experiments. The red mutant class had high levels of phycoerythrin in both red and green light and no inducible phycocyanin in red light. Thus, this mutant behaved as if it were always in green light, regardless of light conditions. Blue mutants exhibite
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10. β-Amylase from Mustard (Sinapis alba L.) Cotyledons 1: Immunochemical Evidence for Synthesis de Novo during Photoregulated Seedling Development
A polyclonal antiserum against mustard (Sinapis alba L.) β-amylase was obtained by injecting a homogeneously purified enzyme preparation in rabbits. The formation of β-amylase specific antibodies was confirmed by staining the precipitin line in double diffusion gel for β-amylase activity. The monospecificity of antiserum against mustard β-amylase was als
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11. Photoregulation of Nicotinamide Adenine Dinucleotide Kinase Activity in Cell-free Extracts 1
This article gives evidence that NAD kinase activity is controlled by the action of phytochrome. The NADP level rapidly increased in the cotyledons of seedlings of Pharbitis nil strain Violet (a short day plant), when the inductive dark for flowering was interrupted with a 5-minute illumination of red light. Illumination with far red light immediately after
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12. Direct observation of the (forbidden) S1 state in carotenoids
Carotenoids are involved in a variety of biological functions, yet the underlying mechanisms are poorly understood, in part because of the long-standing difficulty in assigning the location of the first excited (S1) state. Here, we present a method for determining the energy of the forbidden S1 state, on the basis of ultrafast spectroscopy of the short lived
The National Academy of Sciences.