scholarly journals THE GENETICS OF CHLOROPHYLL BIOSYNTHESIS: LIGHT-INDEPENDENT AND LIGHT-DEPENDENT PATHWAYS

2010 ◽  
Vol 8 (3) ◽  
pp. 38-51 ◽  
Author(s):  
Elena M Chekunova

 The review summarizes contemporary genetical, molecular biological and biochemical data on the two protochlorophyllide oxidoreductases (POR), enzymes responsible of light-dependent (LPOR) and dark-operative (DPOR) protochlorophyllide reduction. Evolutionary aspects of origin and functioning of these enzymes are also discussed. The main focus of this review will be the genetics of archaic dark chlorophyll biosynthesis.

2010 ◽  
Vol 15 (11) ◽  
pp. 614-624 ◽  
Author(s):  
Christiane Reinbothe ◽  
Majida El Bakkouri ◽  
Frank Buhr ◽  
Norifumi Muraki ◽  
Jiro Nomata ◽  
...  

Author(s):  
George C. Ruben ◽  
Kenneth A. Marx

In vitro collapse of DNA by trivalent cations like spermidine produces torus (donut) shaped DNA structures thought to have a DNA organization similar to certain double stranded DNA bacteriophage and viruses. This has prompted our studies of these structures using freeze-etch low Pt-C metal (9Å) replica TEM. With a variety of DNAs the TEM and biochemical data support a circumferential DNA winding model for hydrated DNA torus organization. Since toruses are almost invariably oriented nearly horizontal to the ice surface one of the most accessible parameters of a torus population is annulus (ring) thickness. We have tabulated this parameter for populations of both nicked, circular (Fig. 1: n=63) and linear (n=40: data not shown) ϕX-174 DNA toruses. In both cases, as can be noted in Fig. 1, there appears to be a compact grouping of toruses possessing smaller dimensions separated from a dispersed population possessing considerably larger dimensions.


2018 ◽  
Author(s):  
F Errabie ◽  
A Elmekkaoui ◽  
W Khannoussi ◽  
G Kharrasse ◽  
Z Ismaili

Author(s):  
المختار الأحمر

الملخّص يتناول البحث علاقة الفطرة بالشريعة في التفكير الإسلامي، وما تطرحه هذه العلاقة سواء على مستوى بيان الجوانب المتعلقة بخَلْق الإنسان وما فُطِر عليه ابتداء، وهذا البعد يمثّل الجانب التكوني في مفهوم الفطرة، أو على المستوى المتعلق بالشريعة وفطريتها، أي أنها جارية وفق ما يدركه العقل وتشهد به الفطرة، وهذا البعد يمثّل الجانب التشريعي الذي يطرحه مفهوم الفطرة. لقد زخرت أغلب الكتابات بتناول جانبا واحدا مما يتيحه أو يعكسه مفهوم الفطرة، لكن البحث في العلاقة التناسبية بين الفطرة والشريعة، وما يتيحه هذا النظر المتلازم بين المفهومين على مستوى الإمكانات المتعلقة بقدرات الإنسان الفطرية في فهم وتعقّل الخطاب الشرعي والأحكام التكليفية، والوقوف على غاياته ومقاصده، يبقى في حاجة إلى البحث والاستقصاء. ولذلك تأتي هذه الدراسة لتسليط الضوء على الجانب التشريعي والتكويني في علاقة الشريعة بالفطرة، باعتبارهما نظامين متلازمين يتيحان فهم طبيعة الشريعة وأحكامها ومقاصدها من جهة، وتحديد جوهر وماهية الإنسان الفطرية وإمكاناته في تعقّل هذه الشريعة من جهة ثانية.                  الكلمات المفتاحية: الفطرة، الشريعة، الدين، التكاليف، العقل. Abstract This research addresses the relationship between premordial human nature (fitrah) and Islamic law (SharÊÑah) within the frame of Islamic thought, while exploring the questions it raises at two levels. The first level explains the aspects related to the creation of man and what has initially been bestowed upon him, which represents the evolutionary aspect of the concept of fiÏrah. The second level is related to SharÊÑah and its nature, which evolves according to what is percieved by reason and witnessed by fiÏrah; this represents the legislative aspect presented by the concept of fiÏrah. The majority of studies to date address a single aspect of the illustrations of the concept of fiÏrah. However, research on the dialectic relationship between fiÏrah and SharÊÑah and what its relevant concurrent view provides at the level of potentials related to human innate capacities in understanding and realizing SharÊÑah discourse and mandatory provisions as well as understanding its objectives  remains scarce and requires further research and investigation. Therefore, this study intends to shed light on the legislative and evolutionary aspects of the relationship between SharÊÑah and fiÏrah as two interconnected systems that allow for the understanding of the nature of SharÊÑah, its provisions and purposes, as well as identifying the essence of human innate nature and its potential in perceiving SharÊÑah. Keywords: human nature (fiÏrah), Islamic law (SharÊÑah), religious mandates (TakÉlif), religion, intellect (ÑAqal).


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