Chemistry Commons^™

Synthesis Of Novel Isoprenoid Diphosphate Analogs As Chemical Tools To Investigate Protein Geranylgeranylation, Kayla Jo Temple

Open Access Dissertations

Many proteins require prenylation in order to be biologically functional. Some such proteins include the small Ras and Rho GTPase superfamilies, nuclear lamins A and B, and the kinesin motor proteins CENP-E and F. Prenyltransferase (PTase) inhibition is currently being explored as a possible treatment not only for cancer but for a wide variety of other diseases.

Clinical studies revealed that the effectiveness of farnesyltransferase inhibitors (FTIs) to treat Ras-dependent tumors is determined by which isoform of Ras is overactive. Unfortunately the majority of Ras-dependent tumors have a mutation in either the N- or K-Ras isoforms; both of these isoforms …

Implementation Of A Research-Based Lab Module In A High School Chemistry Curriculum: A Study Of Classroom Dynamics, Matthew Pilarz

Open Access Dissertations

Pilarz, Matthew. Ph.D., Purdue University, December 2013. Implementation of a Research-Based Lab Module in a High School Chemistry Curriculum: A Study of Classroom Dynamics. Major Professor: Gabriela C. Weaver.

For this study, a research-based lab module was implemented in two high school chemistry classes for the purpose of examining classroom dynamics throughout the process of students completing the module. A research-based lab module developed for use in undergraduate laboratories by the Center for Authentic Science Practice in Education (CASPiE) was modified and implemented in two high school settings. This module consisted of four phases: Skill Building, Experimental Design, Independent Research, …

Silica Colloidal Crystals As Emerging Materials For The High-Throughput Sizing Of Proteins By Packed Capillary Electrophoresis, Nadine K. Njoya

Open Access Dissertations

Protein heterogeneity is currently one of the leading problems in formulation of therapeutic proteins. The effectiveness of therapeutic proteins is diminished when they exhibit heterogeneity due to aggregates and degradation by-products. Furthermore, guidelines set forth by the FDA require therapeutic proteins to have high stability as well as high purity. With development time on the order of years and costs incurred in the millions, pharmaceutical companies are investing more time in finding fast and efficient ways to screen for protein heterogeneity. Current methods such as native polyacrylamide gel electrophoresis (PAGE), size-exclusion chromatography (SEC) and capillary electrophoresis (CE) are time consuming, …

Utilizing Electron Microscopy And Spectroscopy Methods To Understand Water Structure And Water Doping, Lior Miller

Open Access Dissertations

Water is the second most common element in the universe and the most studied material on earth. Most of the studies concerning water are from the fields of chemistry and biology. Hence, the structure of water molecules and short range order and interactions are well characterized and understood. However, the collective arrangement of water molecules and the long range order are still missing. Understanding of this long range order in water is needed, as it is the key to many water activities.

To fill this gap, this study utilizes a new direct method for characterization of water in the vapor …

The Effect Of Composition On The Linear And Nonlinear Mechanical Properties Of Particulate Filled Elastomers, Oluwaseyi Ogebule

Open Access Dissertations

Engineering elastomers are materials capable of undergoing large deformation upon load application and recovering upon load removal. From car tires to building vibration isolator systems, elastomers are the most versatile of engineering materials. The inclusion of particulate fillers into elastomers enhances their mechanical properties (modulus, tensile strength, toughness, tear resistance, etc) thereby extending their applicability to more demanding functions. The automotive, healthcare, construction, adhesives and consumer products are some of the many industries that produce finished goods containing elastomeric parts.

Despite the various concepts on reinforcement in filled elastomers, a complete understanding of their linear viscoelastic properties and the nonlinear …

Spectroscopic Characterization Of The Water-Oxidation Intermediates In The Ru-Based Catalysts For Artificial Photosynthesis, Dooshaye Moonshiram

Open Access Dissertations

Utilization of sunlight requires solar capture, light-to-energy conversion and storage. One effective way to store energy is to convert it into chemical energy by fuel-forming reactions, such as water splitting into hydrogen and oxygen. Ruthenium complexes are among few molecular-defined catalysts capable of water splitting. Insight into the mechanism of their action will help to design future robust and economically feasible catalysts for light-to-energy conversion. Mechanistic insights about the design of such catalysts can be acquired through spectroscopic analysis of short-lived intermediates of catalytic water oxidation. Development of time-resolved approaches through stopped flow UV-Vis Spectroscopy to follow the catalysis of …

Top-Down Interrogation And Characterization Of Biological Macromolecules, Yang Gao

Open Access Dissertations

Analytical mass spectrometry has been widely applied in the field of biomolecule identification and characterization. It provides fast, accurate and robust information relevant to the molecular mass, composition and structure of the target analytes.

This thesis is focused on the top-down analysis of various macrobiomolecules, nucleic acids and proteins, in the context of ion/ion reaction and gas-phase unimolecular dissociation. The first part of the thesis deals with gas phase fragmentation behavior of chemically modified oligonucleotides. Factors, such as the observation time-scale, the ion type and the energy deposition method, are explored using a quadrupole/time-of-flight mass spectrometer. Novel fragmentation pathway associated …

Structural Analysis Of Carbohydrates By Mass Spectrometry, Chiharu Konda

Open Access Dissertations

Protein glycosylation is a highly frequent post-translational modification. Glycosylation is actively involved in intermolecular and intercellular binding events that are important to a wide range of biological functions such as immunity and fertility. The unique functions of glycans are directly related to their structures. In order to fully characterize the structure of an unknown glycan, 5 levels of structural information is needed: sugar unit identity, anomeric configuration, linkage types, sequence, and branching location. One of the grand challenges limiting the advance of glycosciences is the lack of sensitive tools for detailed glycan structural analysis. Tandem mass spectrometry (MS/MS) is a …

Mass Spectrometric Studies On The Primary Products Of Fast Pyrolysis Of Carbohydrates And The Molecular Structures Of Asphaltenes, And The Development Of A Rastering Probe For Laser-Induced Acoustic Desorption Into An Atmospheric Pressure Chemical Ionization Source, Matthew Robert Hurt

Open Access Dissertations

Mass spectrometry (MS) has proven invaluable in the field of mixture analysis and structural elucidation. Tandem mass spectrometry (MS/MS) utilizing collision-activated dissociation (CAD) has become the technique of choice for structural elucidation of unknown analytes in mixtures. When coupled with gas chromatography (GC) or high performance liquid chromatography (HPLC), it allows for trace level analysis of mixture components. In spite of the utility of mass spectrometry in complex mixture analysis, it does have limitations. Traditional GC/MS methods used for the analysis of fast pyrolysis products cannot be used to analyze the primary products, thus limiting the knowledge that can be …

Continued Progress Towards Efficient Syntheses Of Cephalostatin North 1 Analogs, Daniel Preston Jamieson

Open Access Dissertations

Jamieson, Daniel P. Ph.D., Purdue University, December 2013. Continued Progress Towards Efficient Syntheses of Cephalostatin North 1 Analogs. Major Professor: PhilipL. Fuchs.

The cephalostatins and ritterazines represent an intriguing class of marine natural products in both structure and biological activity, and the progress towards the synthesis of high valued analogs with a focus on process orientated methodology is described herein. Included in the pages to follow, is the further advancement of the `Red-Ox' strategy toward the highly efficient synthesis of 25-epi-4,15-dihydro-North 1, Chapter 2. A short review focusing on the earlier efforts toward the main synthetic challenges of North 1 …

Fluorous- Phase Synthesis Of Heparan Sulfate Disaccharides & Low-Molecular Weight Additives For Enhancing The Performance Of Lithium-Ion Batteries., Matthew Daniel Casselman

Open Access Dissertations

Heparan sulfate is a complex cell-surface proteoglycan that serves many important roles in biology, such as growth and development, immune response and pathogenesis. Heparan sulfate is structurally heterogeneous due to the variable post- glycosylation modifications, particularly the generation of diverse sets of sulfate esters (sulfoforms) for any given disaccharide unit. In order to establish useful relationships between heparan sulfate structure and biological activity, a set of well-defined sulfoforms is necessary to support binding affinity screening. In this thesis, we describe the generation of diverse sulfoforms from heparan disaccharides using a fluorous tag to facilitate purification of highly charged intermediates, and …

Spectroscopic And Kinetic Study Of Copper-Exchanged Zeolites For The Selective Catalytic Reduction Of Nox With Ammonia, Shane Adam Bates

Open Access Dissertations

The recent application of metal-exchanged, small-pore zeolites for use in the selective catalytic reduction (SCR) of NO_x with ammonia NH₃ for automotive deNO_x applications has been a great stride in achieving emission standard goals. Copper-exchanged SSZ-13 (Cu-SSZ-13), the small-pore zeolite in this study, has been shown to be very hydrothermally stable and active under conditions presented in the exhaust of the lean-burn diesel engine. In this work, detailed studies were performed to identify many aspects of the active site(s) in Cu-SSZ-13 in order to learn about the standard SCR mechanism.

A series of seven Cu-SSZ-13 samples were …

Osmium Catalyzed Dihydroxylation And Oxidative Cleavage Of Vinyl Sulfone And Elucidation Of The Vinylsulfone Polypropionate Methodology For The Synthesis Of The C32 Des-Methyl C28-C34 Actin Binding Tail Of Aplyronine A, Thomas Paul Bobinski

Open Access Dissertations

A general methodology for the generation of dipropionate functionalities using cyclic 7-membered vinylsulfones has been devised for the purpose of synthesizing polyketide natural products such as aplyronine A. Final oxidative cleavage via ozonolysis has been shown to be difficult providing variable yields. Furthermore, elegant synthesis of the C28-C34 segment of the aplyronine A actin binding tail has proved elusive. Utilization of OsO4 and catalytic citric acid has led to a methodology whereby harsh ozonolysis procedures can be mostly avoided. A reengineering of the vinylsulfone polypropionate methodology in conjunction with osmylation has been found to provide the actin binding tail under …

Novel Modulation Of Adenylyl Cyclase Type 2, Jason Michael Conley

Open Access Dissertations

Adenylyl cyclase isoforms are distinctly modulated by G protein subunits and are therefore hypothesized to be uniquely regulated by proteins that influence G protein signaling. Activator of G protein signaling 3 (AGS3) is a G protein modulator that binds Gαi subunits in the GDP-bound state, implicating AGS3 as an important regulatorof Gi-coupled receptor signaling. We studied the ability of AGS3 to modulate recombinant adenylyl cyclase(AC) type 1 and 2 signaling in HEK293 cells following both acute and persistent activation of the D _2Ldopamine receptor (D_2L DR). AGS3 expression modestly enhanced the potency of acute quinpirole-induced D _2LDR …

Conversion Of Iodide To Hypoiodous Acid And Iodine In Aqueous Microdroplets Exposed To Ozone, Elizabeth A. Pillar, Marcelo I. Guzman, Jose M. Rodriguez

Chemistry Faculty Publications

Halides are incorporated into aerosol sea spray, where they start the catalytic destruction of ozone (O₃) over the oceans and affect the global troposphere. Two intriguing environmental problems undergoing continuous research are (1) to understand how reactive gas phase molecular halogens are directly produced from inorganic halides exposed to O₃ and (2) to constrain the environmental factors that control this interfacial process. This paper presents a laboratory study of the reaction of O₃ at variable iodide (I^–) concentration (0.010–100 μM) for solutions aerosolized at 25 °C, which reveal remarkable differences in the reaction intermediates …

On The Origin Of Mode- And Bond-Selectivity In Vibrationally Mediated Reactions On Surfaces, Daniel Killelea, Arthur L. Utz

Chemistry: Faculty Publications and Other Works

The experimental observations of vibrational mode- and bond-selective chemistry at the gas–surface interface indicate that energy redistribution within the reaction complex is not statistical on the timescale of reaction. Such behavior is a key prerequisite for efforts to use selective vibrational excitation to control chemistry at the technologically important gas–surface interface. This paper outlines a framework for understanding the origin of non-statistical reactivity on surfaces. The model focuses on the kinetic competition between intramolecular vibrational energy redistribution (IVR) within the reaction complex, which in the long-time limit leads to statistical behavior, and quenching, scattering, or desorption processes that restrict the …

Structural Evidence: A Single Charged Residue Affects Substrate Binding In Cytochrome P450 Bm-3, Jaclyn Catalano, Kianoush Sadre-Bazzaz, Gabriele A. Amodeo, Liang Tong, Ann Mcdermott

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Cytochrome P450 BM-3 is a bacterial enzyme with sequence similarity to mammalian P450s that catalyzes the hydroxylation of fatty acids with high efficiency. Enzyme-substrate binding and dynamics has been an important topic of study for cytochromes P450 because most of the crystal structures of substrate-bound structures show the complex in an inactive state. We have determined a new crystal structure for cytochrome P450 BM-3 in complex with N-palmitoylglycine (NPG), which unexpectedly showed a direct bidentate ion pair between NPG and arginine 47 (R47). We further explored the role of R47, the only charged residue in the binding pocket in cytochrome …

Molecular Characteristics Of The Water Soluable Organic Matter In Size Resolved Aerosols Collected Over The North Atlantic Ocean, Sarah Catherine Gurganus

Chemistry & Biochemistry Theses & Dissertations

Aerosol particulate matter is acknowledged to have effects on health and the environment and further investigation into the molecular characteristics of aerosols is necessary in order to fully understand the potential links between the molecular characteristics and the impacts that these particles have on health and the environment. Aerosols are often discussed with reference to their size because particles of different sizes can often be associated with different primary sources. This study presents a molecular-level chemical characterization of the water soluble organic matter fraction of 17 aerosol impactor samples representing 3 air mass influences (North American, North African, and marine) …

Efektivitas Sekolah Menengah Kejuruan Berstandar Iso 9001:2008 Terhadap Pencapaian Standar Isi, Standar Proses, Dan Standar Kompetensi Lulusan, Yeni Ratih Pratiwi

Jurnal Pendidikan Sains

Penelitian ini bertujuan untuk mengetahui perbedaan efektivitas pencapaian standar isi, standar proses, dan standar kompetensi lulusan pada Sekolah Menengah Kejuruan (SMK) yang telah menerapkan standar mutu ISO 9001:2008 dan SMK yang belum menerapkannya, baik pada sekolah negeri maupun swasta. Pengumpulan data dilakukan menggunakan kuesioner tertutup dengan skala Likert. Analisis data menggunakan uji ANOVA satu arah dengan bantuan program SPSS. Hasil penelitian menunjukkan bahwa terdapat perbedaan efektivitas antara SMK negeri berstandar ISO dan SMK swasta berstandar ISO (p = 0,001), antara SMK negeri berstandar ISO dan SMK negeri belum berstandar ISO (p = 0,000), serta antara SMK negeri berstandar ISO dan …

Pengaruh Penggunaan Peta Konsep Dalam Pembelajaran Inkuiri Terbimbing Ditinjau Dari Kemampuan Bernalar Siswa Kelas Xi, Agung Wahyudi

Jurnal Pendidikan Sains

Penelitian ini bertujuan untuk: (1) mengetahui perbedaan hasil belajar fisika antara siswa yang belajar menggunakan pembelajaran inkuiri terbimbing melalui peta konsep (PITPK) dan siswa yang belajar menggunakan pembelajaran inkuiri terbimbing (PIT); (2) menguji interaksi antara model pembelajaran dan kemampuan bernalar terhadap hasil belajar fisika; (3) mengetahui efektivitas PITPK dibandingkan PIT pada siswa dengan kemampuan bernalar tinggi; dan (4) mengetahui efektivitas PITPK dibandingkan PIT pada siswa dengan kemampuan bernalar rendah. Penelitian ini menggunakan rancangan faktorial 2 × 2 dengan teknik pengambilan sampel simple random sampling. Instrumen penelitian meliputi instrumen perlakuan berupa silabus, RPP, dan lembar observasi keterlaksanaan pembelajaran, serta instrumen pengukuran …

Pengaruh Pendekatan Genius Learning Berbasis Kerja Ilmiah Terhadap Prestasi Belajar Fisika Ditinjau Dari Pengetahuan Awal Siswa Smpn 13 Balikpapan Tahun 2012, Suliyono Suliyono

Jurnal Pendidikan Sains

Penguasaan konsep-konsep fisika siswa akan lebih optimal apabila pendidik menerapkan strategi pembelajaran yang mampu meningkatkan keaktifan dan motivasi belajar siswa dengan tetap berlandaskan pada pendekatan konstruktivis. Pendekatan Genius Learning Berbasis Kerja Ilmiah (GLBKI) diyakini mampu menjawab tuntutan perkembangan pendidikan serta mempermudah siswa dalam mempelajari konsep-konsep fisika. Penelitian ini bertujuan untuk menguji perbedaan prestasi belajar fisika antara siswa yang belajar menggunakan pendekatan Genius Learning Berbasis Kerja Ilmiah dan siswa yang belajar menggunakan pembelajaran konvensional. Penelitian ini menggunakan desain eksperimen dengan pemberian perlakuan berupa pendekatan GLBKI pada kelas eksperimen yang dipilih secara acak, sedangkan kelas kontrol diberikan pembelajaran konvensional. Data prestasi belajar …

Peer Mediated Instruction And Intervention (Pmii) Tipe Classwide Peer Tutoring (Cwpt) Dan Kemampuan Akademik Pada Pembelajaran Ipa Biologi Smk, Hamsiah Hamsiah

Jurnal Pendidikan Sains

Pembelajaran IPA di SMKN 1 Bontang masih didominasi dengan strategi belajar konvensional yaitu metode belajar dengan ceramah. Hal ini berdampak terhadap hasil belajar kognitif IPA biologi yang cenderung masih rendah karena siswa belum terlatih menjadi pebelajar yang mandiri, sehingga inovasi pembelajaran PMII tipe CWPT dapat digunakan sebagai terobosan untuk mengembangkan hasil belajar kognitif. Penelitian ini dilakukan untuk mengetahui penerapan strategi CWPT dan kemampuan akademik pada pembelajaran IPA Biologi SMK. Penelitian eksperimen semu dengan rancangan pretest-posttest Nonequivalent Control Group. Hasil penelitian, yaitu: (1) ada pengaruh CWPT terhadap hasil belajar kognitif, (2) ada pengaruh kemampuan akademik terhadap hasil belajar kognitif, dan (3) …

Pengaruh Penerapan Model Pembelajaran Pemerolehan Konsep Dipadu Pembelajaran Kooperatif Stad Terhadap Prestasi Belajar, Keaktifan, Dan Respons Siswa Pada Pembelajaran Ikatan Kimia, Putri Ridha Ilahi

Jurnal Pendidikan Sains

Penelitian ini bertujuan untuk mengetahui perbedaan: (1) prestasi belajar siswa menggunakan model pembelajaran pemerolehan konsep dipadu pembelajaran kooperatif STAD dan prestasi belajar siswa menggunakan model pembelajaran pemerolehan konsep dalam pembelajaran konvensional; (2) keaktifan siswa menggunakan model pembelajaran pemerolehan konsep dipadu pembelajaran kooperatif STAD dan keaktifan siswa menggunakan model pembelajaran pemerolehan konsep dalam pembelajaran konvensional; (3) respon siswa terhadap pembelajaran pemerolehan konsep dipadu pembelajaran kooperatif STAD dan respon siswa terhadap pembelajaran pemerolehan konsep dalam pembelajaran konvensional. Penelitian ini menggunakan rancangan penelitian deskriptif dan rancangan eksperimen semu (quasy experiment design). Data prestasi belajar dikumpulkan menggunakan tes objektif dan koefisien reliabilitas dihitung dengan …

Degradasi Anaerob Sampah Organik Dengan Bioaktivator Effective Microorganism-5 (Em-5) Untuk Menghasilkan Biogas, Metri Dian Insani

Jurnal Pendidikan Sains

Tujuan penelitian ini adalah untuk: (1) menganalisis perbedaan penggunaan tongkol jagung, kelaras pisang, dan kulit pisang dengan penambahan kotoran sapi terhadap tekanan biogas, (2) menganalisis perbedaan penggunaan tongkol jagung, kelaras pisang, dan kulit pisang dengan penambahan kotoran sapi terhadap lama waktu nyala api biogas yang dihasilkan, dan (3) menganalisis perbedaan penggunaan tongkol jagung, kelaras pisang, dan kulit pisang dengan penambahan kotoran sapi terhadap rasio C/N akhir. Penelitian eksperimen didesain menggunakan rancangan acak lengkap (RAL), dengan tiga perlakuan masing-masing dalam 3 kali ulangan. Hasil penelitian membuktikan bahwa: (1) terdapat perbedaan tongkol jagung, kelaras pisang, dan kulit pisang dengan penambahan kotoran sapi …

Relevansi Soft Skill Yang Dibutuhkan Dunia Usaha/Industri Dengan Yang Dibelajarkan Di Sekolah Menengah Kejuruan, Didik Suryanto

Jurnal Pendidikan Sains

Penelitian ini bertujuan untuk mendeskripsikan relevansi soft skill yang dibutuhkan oleh dunia usaha dan industri dengan soft skill yang dibelajarkan di Sekolah Menengah Kejuruan (SMK) di Kabupaten Blitar. Instrumen penelitian yang digunakan berupa angket atau kuesioner. Data dianalisis menggunakan teknik analisis deskriptif kuantitatif. Hasil penelitian menunjukkan bahwa terdapat sejumlah soft skill yang relevan antara kebutuhan dunia usaha/industri dan pembelajaran di SMK menurut persepsi guru dan siswa, yaitu: (a) kejujuran dan sikap perilaku yang baik, (b) rasa tanggung jawab, (c) disiplin waktu, (d) kemampuan bekerja secara aman, (e) ketangguhan atau kegigihan dalam bekerja, (f) kemampuan mengatasi stres, (g) kemandirian atau tidak …

Penggunaan Media Bangun Geometri Untuk Menanamkan Konsep Penjumlahan Pecahan, Nanik Ulfa

Jurnal Pendidikan Sains

Pemahaman konsep merupakan aspek penting dalam pembelajaran matematika. Untuk menanamkan pemahaman konsep pada siswa yang masih berada pada tahap berpikir konkret, diperlukan bantuan media pembelajaran yang akrab dengan siswa. Dalam penelitian ini, media yang digunakan adalah media bangun geometri bidang. Penggunaan media tersebut diharapkan mampu menciptakan suasana pembelajaran yang menyenangkan serta mendorong keterlibatan aktif siswa dalam proses pembelajaran. Pembelajaran dilaksanakan melalui tiga tahap, yaitu: (1) tahap awal untuk mengecek pengetahuan prasyarat siswa, (2) tahap inti, pada tahap ini siswa memanipulasi media bangun geometri sesuai dengan panduan dalam Lembar Kerja Siswa (LKS) yang disusun oleh peneliti, dan (3) tahap penutup, yaitu …

Pengembangan Media Pembelajaran Interaktif Untuk Membangun Pemahaman Konsep Garis Singgung Persekutuan Dua Lingkaran, Vivin Nur Afidah

Jurnal Pendidikan Sains

Media pembelajaran interaktif yang dikembangkan adalah media pembelajaran interaktif yang dirancang berdasarkan karakteristik pembelajaran dengan bantuan komputer/Computer Assisted Instruction (CAI) tipe tutorial. Dirancang berdasarkan teori beban kognitif yaitu meminimalkan pemrosesan beban kognitif extraneous, mengatur pemrosesan beban kognitif intrinsic, dan mengembangkan pemrosesan beban kognitif germane. Penelitian pengembangan mengikuti model pengembangan 4D yaitu define (pendefinisian), design (perancangan), develop (pengembangan), dan disseminate (penyebarluasan). Simpulannya adalah (1) hasil validasi oleh ahli dan praktisi menilai media pembelajaran interaktif yang dikembangkan valid, (2) hasil pengamatan aktivitas guru dan siswa menunjukkan media pembelajaran interaktif memenuhi kriteria kepraktisan, (3) hasil kuis menunjukkan sebagian besar siswa mencapai tingkat pemahaman …

Pengembangan Buku Kerja Materi Eksponen Bercirikan Rme Untuk Siswa Smk Teknik, Sri Widowati

Jurnal Pendidikan Sains

Tujuan penelitian pengembangan ini adalah menghasilkan buku kerja berbahasa Inggris materi eksponen yang bercirikan Realistic Mathematics Education (RME) untuk siswa Sekolah Menengah Kejuruan (SMK) teknik kelas X serta memenuhi kriteria valid, praktis dan efektif. Proses validasi ahli dilakukan untuk mengetahui tingkat kevalidan buku kerja yang dihasilkan. Proses uji coba dilakukan untuk mengetahui tingkat kepraktisan dan keefektifan dari buku kerja yang dihasilkan. Berdasarkan proses validasi, diperoleh hasil bahwa buku kerja yang dihasilkan memenuhi kategori valid. Sedangkan dari proses uji coba diperoleh bahwa keterlaksanaan pembelajaran dengan menggunakan buku kerja berada pada kriteria praktis. Selain itu, rata-rata siswa memberikan respon positif dan hasil …

Pengaruh Model Pembelajaran Arias Dan Arias Dipadu Peta Konsep Terhadap Kemampuan Berpikir Kritis, Kognitif, Dan Afektif, Ismail Ismail

Jurnal Pendidikan Sains

Model pembelajaran Assurance, Relevance, Interest, Assessment, dan Satisfaction (ARIAS) dipadu peta konsep dapat meningkatkan kemampuan berpikir kritis, kognitif, dan afektif. Penelitian bertujuan untuk menguji pengaruh model pembelajaran ARIAS, ARIAS dipadu peta konsep, dan peta konsep terhadap kemampuan berpikir kritis, kognitif, dan afektif. Data penelitian dikumpulkan melalui tes uraian dan lembar observasi. Hasil analisis data menunjukkan bahwa nilai rata-rata kemampuan berpikir kritis, kognitif dan afektif untuk kelompok model pembelajaran ARIAS dipadu Peta Konsep tergolong kategori sangat baik, kelas perlakuan pembelajaran ARIAS, dan kelas perlakuan Peta Konsep termasuk kategori baik.

Keefektifan Gambar Statis, Gambar Dinamis Ball-And-Stick, Dan Model Molekul Sederhana Yang Dibuat Dari Jarum Pentul Pada Pembelajaran Bentuk Dan Kepolaran Molekul, Muhammad Ardiansyah

Jurnal Pendidikan Sains

Tujuan penelitian ini adalah untuk membandingkan keefektifan gambar statis, gambar dinamis ball-and-stick, dan model molekul sederhana dibuat dari jarum pentul ditinjau dari hasil belajar kognitif siswa pada pembelajaran bentuk dan kepolaran molekul. Data penelitian adalah skor hasil belajar kognitif siswa yang dikumpulkan dengan menggunakan tes pilihan ganda yang terdiri dari 35 item dengan validitas isi tes sebesar 87,6%, dan koefisien reliabilitas, dihitung dengan rumus KR-21, sebesar 0,90. Data penelitian dianalisis menggunakan statistik uji t. Hasil penelitian menunjukkan bahwa skor hasil belajar kognitif siswa yang diperoleh dari pembelajaran bentuk dan kepolaran molekul dengan menggunakan model molekul sederhana dibuat dari jarum pentul …