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A growing body of evidence has shown that active learning has a considerable advantage over traditional lecture for student learning in undergraduate STEM classes, but there have been few large-scale studies to identify the specific types of activities that have the greatest impact on learning. We therefore undertook a large-scale, curriculum-wide study to investigate the effects of time spent on a variety of classroom activities on learning gains. We quantified classroom practices and related these to student learning, assessed using diagnostic tests written by over 3700 students, across 31 undergraduate biology classes at a research-intensive university in the Pacific Northwest. The most significant positive predictor of learning gains was the use of group work, supporting the findings of previous studies. Strikingly, we found that the addition of worksheets as an active learning tool for in-class group activities had the strongest impact on diagnostic test scores. This particular low-tech activity promotes student collaboration, develops problem solving skills, and can be used to inform the instructor about what students are struggling with, thus providing opportunities for valuable and timely feedback. Overall, our results indicate that group activities with low barriers to entry, such as worksheets, can result in significant learning gains in undergraduate science. [ABSTRACT FROM AUTHOR]

This review article includes our analysis of the literature and our own experiences in using various types of active learning as best practices for evidencebased teaching in physiology. We have evaluated what physiology students should be expected to learn and what are specific challenges to enhancing their learning of physiology principles. We also consider how the instructor should design his or her teaching to improve buy-in from both students and other faculty members. We include a discussion of how the readers can evaluate their teaching approaches for their successes in enhancing student learning of physiology. Thus we have addressed pedagogical improvements specific to student learning of physiology, with additional suggestions from cognitive psychology approaches that can improve physiology teaching and learning. [ABSTRACT FROM AUTHOR]

Processing α-glucosidase I (GluI) is a key member of the eukaryotic N-glycosylation processing pathway, selectively catalyzing the first glycoprotein trimming step in the endoplasmic reticulum. Inhibition of GluI activity impacts the infectivity of enveloped viruses; however, despite interest in this protein from a structural, enzymatic, and therapeutic standpoint, little is known about its structure and enzymatic mechanism in catalysis of the unique glycan substrate Glc3Man9GlcNAc2. The first structural model of eukaryotic GluI is here presented at 2-Å resolution. Two catalytic residues are proposed, mutations of which result in catalytically inactive, properly folded protein. Using Autodocking methods with the known substrate and inhibitors as ligands, including a novel inhibitor characterized in this work, the active site of GluI was mapped. From these results, a model of substrate binding has been formulated, which is most likely conserved in mammalian GluI. [ABSTRACT FROM AUTHOR]

Abstract: Eukaryotic N-glycoprotein processing in the endoplasmic reticulum begins with the catalytic action of processing α-glucosidase I (αGlu). αGlu trims the terminal glucose from nascent glycoproteins in an inverting-mechanism glycoside hydrolysis reaction. αGlu has been studied in terms of kinetic parameters and potential key residues; however, the active site is unknown. A structural model would yield important insights into the reaction mechanism. A model would also be useful in developing specific therapeutics, as αGlu is a viable drug target against viruses with glycosylated envelope proteins. However, due to lack of a high-yielding overexpression and purification scheme, no eukaryotic structural model of αGlu has been determined. To address this issue, we overexpressed the Saccharomyces cerevisiae soluble αGlu, Cwht1p, in the host Pichia pastoris. It was purified in a simple two-step protocol, with a final yield of 4.2mg Cwht1p per liter of growth culture. To test catalytic activity, we developed a modified synthesis of a tetrasaccharide substrate, Glc3ManOMe. Cwht1p with Glc3ManOMe shows a K m of 1.26mM. Cwht1p crystals were grown and subjected to X-ray irradiation, giving a complete diffraction dataset to 2.04Å resolution. Work is ongoing to obtain phases so that we may further understand this fundamental member of the N-glycosylation pathway through the discovery of its molecular structure. [Copyright &y& Elsevier]