31 research outputs found
Türk Biyokimya Dergisi
Characterization of polyphenol oxidase during three ripening stages of an eggplant (Solanum melongena L.) fruit: a local type in northeast Anatolia [Patlıcan (Solanum melongena L.) meyvesinin polifenol oksidazının üç olgunlaşma safhası boyunca karakterizasyonu: Doğu Anadolu' da yerel bir tip] ABSTRACT Objective: A relatively new local type of eggplant, Solanum melongena L. 'Kadife' is widely consumed in Turkey because of its economic availability and good nutritional qualities. However, the high polyphenol content of eggplant renders it susceptible to unattractive oxidative browning catalyzed by polyphenol oxides (PPOs). Therefore, the main aim of this study was to characterize PPO in this eggplant cultivar at three stages of its development. Methods: In this study, we determined substrate specificity, optimum pH and temperature, and optimum substrate concentration of the partial purified eggplant fruits PPO during ripening. Results: L-DOPA was proved to be the preferred PPO substrate in all three stages of ripening. Optimum activity was observed at pH 7.0 for PPO in extracts of ripening and overly-ripe eggplant, while activity in extracts of immature eggplant exhibited a broad pH optimum between, pH 5.0 and 7.0. In general, at all ripening stages, PPO was most active at 30°C and was most sensitive to inhibition by sodium metabisulphite and ascorbic acid. The metal ions (Hg ÖZET Amaç: Kısmen yeni bir yerel tip patlıcan çeşidi Solanum melongena L. 'Kadife', ekonomik uygunluğu ve iyi besin kalitesinden dolayı Türkiye'de yaygın olarak tüketilir. Bununla birlikte, patlıcanın yüksek polifenol içeriği, bu meyveyi polifenol oksidaz (PFO) tarafından katalizlenen istenmeyen oksidatif esmerleşmeye karşı duyarlı kılar. Dolayısıyla, bu çalışmanın temel amacı, gelişiminin üç safhasında bu patlıcan kültivarındaki PFO'yu karakterize etmektir. Metod: Bu çalışmada, olgunlaşma boyunca patlıcan meyvelerinden elde edilen kısmi saflaştı-rılmış PFO'nun substrat özgünlüğünü, optimum pH ve sıcaklığını, ve optimum substrat konsantrasyonunu belirledik. Bulgular: Olgunlaşmanın her üç safhasında, L-DOPA'nın tercih edilen PFO substratı olduğu ortaya konuldu. Olgunlaşmamış patlıcan özütlerinde optimum pH 5.0 ile 7.0 arasında geniş bir aktivite gösterirken olgun ve aşırı olgun patlıcan özütlerindeki PFO aktivitesi için optimum pH'nın 7.0 olduğu gözlendi. Genel olarak, tüm olgunlaşma safhalarında, PFO, 30°C'de en aktiftir ve inhibitör olarak sodyum metabisülfit ve askorbik aside oldukça duyarlıdır. Materials and Methods Plant material The seeds belonging to the eggplant (Solanum melongena) were obtained from local growers, but they have not certificated yet
An Analysis of Scores of Prospective Biology Teachers on the Factors of MSLQ
Abstract. The factors of learning strategies and motivation as components of self-regulation are determined well in MSLQ (Motivated Strategies for Learning Questionnaire) scale. The scale includes 15 factors. But, these 15 factors are not appropriate for practical use. In this study, a survey research was conducted with 112 prospective biology teachers by using MSLQ to analyze the factors. One-way ANOVAs and Pearson Product-Moment Correlation Coefficients were used for analysis. The results of ANOVAs showed that there were no statistically significant differences between mean scores of the participants at different grade levels on scales of MSLQ. In addition, the "task value", the "self-efficacy" and the "help seeking" subfactors were found to be the most dominant sub-factors of the whole scale. In the article, results of the study and limitations will be discussed
The Calculation of Represenations of the Group of Overhand Knot
This paper is a continuation of earlier Works of the author [1,2]. The Group of overhand knot is given [2] by G = |x, y: xyx = yxy| The symmetric group of degree four is denoted by S4 and is given as follows [4]: S4 = � � a, b: a 3 = b 4 =(ab) 2 =1 � � where a = (234) and b = (243)(12) Here, the complete classification of G in S4 is given. These calculations are mostly obtained in [6]. These representations are divided into eight non-equivalent classes. For each class a representative homomorphism is considered and the corresponding fundamental group of 4-sheeted covering space of the overhand knot has been calculated by the algorithm of Professor Fox
568 LONGHORNED BEETLES OF KIRIKKALE PROVINCE IN TURKEY (COLEOPTERA: CERAMBYCIDAE)
ABSTRACT: This work is the first attempt for entire longhorned beetles fauna of Kırıkkale. All known taxa from Kırıkkale province are given with new faunistical data in the present text. 31 species are new records for Kırıkkale province. Pedostrangalia verticalis (Germar, 1822) is also the first record for Central Anatolian Region of Turkey. Moreover, Phytoecia rufipes rufipes (Olivier, 1795) is also the first report for the northern half of Turkey