Recent articles:
Use of multimedia technology for stereochemistry teaching at university level
Por Gisela Celeste Muscia, Esteban Ariel Ugliarolo
Teaching chemistry, the biggest drawback is that atoms and molecules are very small structures we have no possibility to observe. Therefore, we use a mental model that is valid for teaching this science. The aim of this work is the implementation of ChemBio3DUltra v11.0 to generate three-dimensional representations and to help improving the quality of the teaching process in relation to traditional teaching. A sample of 200 students enrolled in the Organic Chemistry II course, and the curriculum of Pharmacy and Biochemistry careers, University of Buenos Aires, have participated in the investigation. The study group was composed of 100 students and the control group of another 100. Students were questioned on the usefulness of the topic in the development of stereochemistry. We analyzed their performance in evaluative instance. In our case we observed that the use of ChemBioUltra v11.0 has been useful for students. In the evaluative instance, approximately 50% more students got the highest score compared to the control sample.
KEYWORDS: Stereochemistry, multimedia technology, 3D representation, teaching strategy, university teaching
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Re-creating simulations with spreadsheets
Por
Andrés Raviolo
This paper extends the didactic applications of spreadsheet in chemistry teaching. Four activities are presented: (a) searching and critical analysis of simulations, (b) verification of simulations, (c) re-creation of simulations and (d) overcome of the original simulations. The activities with spreadsheets are accessible and relatively simple for students and teachers.
Keywords: simulations, spreadsheets, chemistry teaching
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E-learning course for first year Engineering students
Por
Cristina Pogliani, Ana María Tocci, Alicia H. Jubert, Alcira Vallejo
One of the difficulties in learning chemistry faced by students of the Engineering Faculty that have not approved the first course and need to course it again is to answer questions such as ¿Why do we need to learn chemistry? ¿Why do I have to learn this, if I know the issue? This led to face a methodology based on the implementation of the “Teaching for Understanding” that was applied in an e-learning chemistry course, with evaluation attendance. We designed a didactic sequence centered on understanding, using “alternative energies” as a central theme and developing four generative topics. Then it was considered necessary to describe the steps for the adaptation of the methodology by designing a teaching sequence through the use of ICT, employing a guided inquiry process with tutorial guide and discussion in on-line forums until the stage of synthesis was reached, which reflects the level of understanding achieved by students. The purpose of this strategy is to improve the performances of understanding in most of the students, and the results encourage us to continue with this proposal and develop other similar ones.
KEYWORDS: general chemistry, teaching for understanding, e-learning, alternative energies
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The relevance of molybdenum in biological systems and its role in the mononuclear enzymes with the Moco cofactor
Por
Noráh Barba Behrens, Juan Iván Gómez-Peralta, Ariadna Garza-Ortiz, Arely Pérez-González
Molybdenum is widely spread among the living systems mainly due to its redox properties. The redox reactions comprise one electron transfer as well as migration of atoms like sulfur, oxygen and hydrogen. Molybdenum is the structural element of two proteinic cofactors that are present in several biological systems: FeMoco, where the polynuclear structure contains a 4Fe-4S and Mo-3Fe-4S clusters; Moco cofactor contains one atom of molybdenum. The former cofactor is present in the enzymes called nitrogenases that are responsible of the nitrogen fixation. Moco is present in a large group of enzymes that are classified in three main families: the xantine oxidase, sulfite oxidase and DMSO reductase. Deficiencies or biochemical abnormalities due to molybdenum and the cofactors that contain this metal have a main contribution in the preservation of life. The molybdenum cofactors are responsible for the nitrogen cycle; additionally in humans, these deficiencies of Mo are associated with neurological damage, xantinuria and gout or hyperuricemia. This paper contains a detailed revision of new evidences in the role of molybdenum and Moco in the biological systems.
Keywords: molybdenum, Moco, FeMoco, xantine oxidorreductase, molybdenum cofactor deficiency (MoCD), sulphite oxidase (SO), aldehyde oxidoreductase (AOR), hyperuricemy, gout
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