PENERAPAN PEMBELAJARAN KOOPERATIF MODEL GROUP INVESTIGATION (GI) UNTUK MENINGKATKAN MOTIVASI DAN HASIL BELAJAR BIOLOGI

Model pembelajaran mempengaruhi motivasi dan hasil belajar Biologi siswa sekolah menengah atas. Berdasarkan observasi awal, diketahui bahwa pembelajaran Biologi di kelas X-1 SMA Negeri 7 Malang memiliki beberapa ciri, yaitu (1) motivasi belajar siswa cenderung kurang, (2) dalam menyelesaikan suatu tugas, siswa dengan karakteristik yang sama cenderung mengelompok sehingga terbentuk kelompok homogen yang tidak seimbang di kelas, dan (3) metode ceramah yang diterapkan oleh guru tidak menarik minat siswa sehingga mempengaruhi hasil belajarnya. Berdasarkan kondisi tersebut maka dilakukan penelitian dengan menggunakan pembelajaran kooperatif model Group Investigation (GI) untuk meningkatkan motivasi dan hasil belajar Biologi siswa. Jenis penelitian ini adalah penelitian tindakan kelas dengan menggunakan pendekatan kualitatif dan dirancang dalam dua siklus. Hasil penelitian menunjukkan penerapan pembelajaran kooperatif model GI dapat meningkatkan motivasi dan hasil belajar Biologi siswa. Motivasi belajar siswa meningkat sebesar 31, 48% yaitu dari 46, 15% dengan kategori cukup pada siklus I menjadi 77, 63% dengan kategori baik pada siklus II. Hasil belajar siswa juga mengalami peningkatan, terlihat dari nilai rata-rata siswa sebesar 81, 94% pada siklus I menjadi 89, 18% pada siklus II dan siswa yang tuntas belajar juga mengalami peningkatan dari 79, 49% pada siklus I menjadi 97, 44 % pada siklus II. Hasil angket juga menunjukkan bahwa siswa menyukai dan lebih termotivasi untuk belajar Biologi setelah mengikuti pembelajaran dengan pembelajaran kooperatif model GI.

Synthesis, Characterization of Novel Curcumin Analogs and Their Biological Activities

Curcumin has shown large number of pharmacological properties against different phenotypes of various disease models. Different synthetic routes have been employed to develop its various derivatives for diverse biological functions. In this study Schiff bases, pyrazoles, pyrimidines and sulfonamides bearing curcumin scaffold were synthesized to investigate their pharmacological effects. The structures of newly synthesized compounds were described by IR, MS, 1H NMR, 13C NMR spectral data and elemental analysis. Antibacterial and antifungal activities were evaluated for compounds (3-14) with Ciprofloxacin, Nystatin and Ketoconazole using disc diffusion method and minimum inhibitory concentration values were determined by 96-well plate assay method. Our studies showed that compound 3 has promising antibacterial (MIC: 15.63-31.25 µg/mL) while compound 5 (MIC: 15.63-250 µg/mL) has better antifungal activity as compared to reference drugs. Similarly the combination of more potent compounds 3 and 5 with Ciprofloxacin and Nystatin respectively gave significant synergic effect (FIC index value ≤ 1). The anti-inflammatory and antinociceptive activities of compounds (3-25) were also evaluated with Indomethacin and Diclofenac sodium in experimental animal models respectively. Compound 20, 21 and 25 exhibited relatively higher prevention of writhing episodes than any other compound with antinociceptive activity of 73.2, 74.9 and 71.8 % respectively whereas compound 3 showed highest anti-inflammatory activity (82.0 % paw edema inhibition). Cyclooxygenase-2 (COX-2) enzyme inhibition was evaluated with these synthesized compounds (3-25) through in vitro cyclooxygenase assays. COX-2 inhibition assays result revealed that compound 25 (75.3 %) was the most active compound. Molecular docking vi studies were also performed to identify the plausible binding mode of these compounds with COX-2. Urease enzyme inhibition was also evaluated through in vitro assays and inhibition assays result revealed that compound 24 was found to be more potent (IC50 = 2.44±0.07 µM) among the tested compounds (3-25). The compounds with diazine ring system showed better urease inhibition (IC50 = 11.43±0.21-19.63±0.28 µM) than the standard urease inhibitor thiourea (IC50 = 22.61±0.23 µM).Kinetic data revealed that compounds 5-7, 24 were competitive inhibitors with Ki values 20.0, 19.87, 20.23 and 19.11 µM respectively. Compounds 26-47 were screened for in vitro carbonic anhydrase-I (human, hCAI) and carbonic anhydrase-II (bovine, bCAII) inhibition assay. Compound 26 showed the Ki 0.99 µM and had more inhibitory activity on hCA-I than Acetazolamide (AZZ). From kinetic studies the Ki values of compound 26, 28 and 42 towards bCAII were 0.71, 0.67 and 0.71 µM respectively. Compound 28 has comparable Ki to AZZ (0.63 µM) towards bCAII. Compounds 48-53 were screened for antibacterial activity, compounds 48 with isoxazole moiety have moderate antibacterial activity against both the gram positive and gram negative bacteria with highest zone of inhibition (18.7 mm) against S. aureus with AI value 56.2 % when compared with Ciprofloxacin having MIC > 500 µg/mL. While the rest of compounds in this series showed poor antibacterial activity.