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1	Acid hydrolysis of neutral glycosphingolipids Nardan, Denise Unknown Date (has links) Blood group glycolipids are important tools in the study of microbial receptor interactions and other biological phenomena. Presently blood group glycolipids of interest are isolated from biological samples. However, all glycolipids are not readily available due to the low frequency of some phenotypes in the general population. The ability to acquire the rare glycolipids from the degradation of common glycolipids would be a useful alternative to trying to obtain the molecules from biological sources.This research set out to establish the ability of blood group glycolipids to be degraded into useful glycolipids in a controlled manner by acid hydrolysis and possibly metal catalysis. The initial experiments investigated the degradation/hydrolysis of the more readily available glycolipid globoside with a range of salts and acids to establish degradation concepts such as; temperature, type of acid, acid concentration, and the role of metal ions in glycolipid degradation. These concepts then led to a series of degradation experiments with the blood group glycolipids Leb and ALeb. These glycolipids were incubated with a range of acid concentrations and varying temperatures. Thin layer chromatography separation and chemical and immunochemical staining were the main methods used to identify the products of degradation.It was established that metal ions were not directly involved in the catalysis of glycolipids in the short-term, however some metal ions were indirectly implicated in their degradation due to their ability to form acid solutions. Acid hydrolysis was established as the principle mechanism for glycan chain degradation. In general it was found that the glycan chain primarily lost its fucose groups (in no particular order) and was then followed by sequential degradation of the remaining glycan chain. The glycan chain also appeared to have a protective function on the ceramide moiety. Degradation of globoside established a simple sequential pathway of glycan chain reduction from the non-reducing end. Blood group glycolipids ALeb and Leb first lost their fucose side groups followed by sequential reduction of the glycan chain. Although not fully controllable, degradation of Leb was able to produce Lea, Led and Lec. In contrast degradation of ALeb did not produce any Lea or Led. Instead A-type 1 and two novel A-like structures, 'linear A' and 'GalNAc-Lea' were generated. Lec was only produced from ALeb in extremely acidic conditions. This research established the ability to generate, by acid hydrolysis, a range of rare and "unnatural" novel glycolipids from more commonly available structures. It is of interest that the so-called unnatural glycolipids obtained from the acid hydrolysis of ALeb may, in theory, occur naturally in the acid environment of the stomach, and as such could have the potential to be implicated in disease. It is probable that by applying the principles learned here, a range of novel and natural structures suitable for use in the study of biological interactions can be obtained. Acid hydrolysis Glycosidic bonds Lewis blood groups Fucose glycolipids A Lewis b Lewis b Lewis c
2	Acid hydrolysis of neutral glycosphingolipids Nardan, Denise Unknown Date (has links) Blood group glycolipids are important tools in the study of microbial receptor interactions and other biological phenomena. Presently blood group glycolipids of interest are isolated from biological samples. However, all glycolipids are not readily available due to the low frequency of some phenotypes in the general population. The ability to acquire the rare glycolipids from the degradation of common glycolipids would be a useful alternative to trying to obtain the molecules from biological sources.This research set out to establish the ability of blood group glycolipids to be degraded into useful glycolipids in a controlled manner by acid hydrolysis and possibly metal catalysis. The initial experiments investigated the degradation/hydrolysis of the more readily available glycolipid globoside with a range of salts and acids to establish degradation concepts such as; temperature, type of acid, acid concentration, and the role of metal ions in glycolipid degradation. These concepts then led to a series of degradation experiments with the blood group glycolipids Leb and ALeb. These glycolipids were incubated with a range of acid concentrations and varying temperatures. Thin layer chromatography separation and chemical and immunochemical staining were the main methods used to identify the products of degradation.It was established that metal ions were not directly involved in the catalysis of glycolipids in the short-term, however some metal ions were indirectly implicated in their degradation due to their ability to form acid solutions. Acid hydrolysis was established as the principle mechanism for glycan chain degradation. In general it was found that the glycan chain primarily lost its fucose groups (in no particular order) and was then followed by sequential degradation of the remaining glycan chain. The glycan chain also appeared to have a protective function on the ceramide moiety. Degradation of globoside established a simple sequential pathway of glycan chain reduction from the non-reducing end. Blood group glycolipids ALeb and Leb first lost their fucose side groups followed by sequential reduction of the glycan chain. Although not fully controllable, degradation of Leb was able to produce Lea, Led and Lec. In contrast degradation of ALeb did not produce any Lea or Led. Instead A-type 1 and two novel A-like structures, 'linear A' and 'GalNAc-Lea' were generated. Lec was only produced from ALeb in extremely acidic conditions. This research established the ability to generate, by acid hydrolysis, a range of rare and "unnatural" novel glycolipids from more commonly available structures. It is of interest that the so-called unnatural glycolipids obtained from the acid hydrolysis of ALeb may, in theory, occur naturally in the acid environment of the stomach, and as such could have the potential to be implicated in disease. It is probable that by applying the principles learned here, a range of novel and natural structures suitable for use in the study of biological interactions can be obtained. Acid hydrolysis Glycosidic bonds Lewis blood groups Fucose glycolipids A Lewis b Lewis b Lewis c
3	Undergraduate Students' Understanding and Interpretation of Carbohydrates and Glycosidic Bonds Jennifer Garcia (16510035) 10 July 2023 (has links) <p>For the projects titled Undergraduate Students’ Interpretation of Fischer and Haworth Carbohydrate Projections and Undergraduate Students' Interpretation of Glycosidic Bonds – there is a prevalent issue in biochemistry education in which students display fragmented knowledge of the biochemical concepts learned when asked to illustrate their understandings (via drawings, descriptions, analysis, etc.). In science education, educators have traditionally used illustrations to support students’ development of conceptual understanding. However, interpreting a representation is dependent on prior knowledge, ability to decode visual information, and the nature of the representation itself. With a prevalence of studies conducted on visualizations, there is little research with a focus on the students’ interpretation and understanding of carbohydrates and/or glycosidic bonds. The aim of these projects focuses on how students interpret representations of carbohydrates and glycosidic bonds. This study offers a description of undergraduate students’ understanding and interpretation using semi-structured interviews through Phenomenography, Grounded Theory and the Resources Frameworks. The data suggests that students have different combinations of (low or high) accuracy and productivity for interpreting and illustrating carbohydrates and glycosidic bonds, among other findings to be highlighted in their respective chapters. More effective teaching strategies can be designed to assist students in developing expertise in proper illustrations and guide their thought process in composing proper explanations in relation to and/or presence of illustrations.</p> <p><br></p> <p>For the project titled Impact of the Pandemic on Student Readiness: Laboratories, Preparedness, and Support – it was based upon research by Meaders et. al (2021) published in the International Journal of STEM Education. Messaging during the first day of class is highly important in establishing positive student learning environments. Further, this research suggests that students are detecting the messages that are communicated. Thus, attention should be given to prioritizing what information and messages are most important for faculty to voice. There is little doubt that the pandemic has had a significant impact on students across the K-16 spectrum. In particular, for undergraduate chemistry instructors’, data on the number of laboratories students completed in high school and in what mode would be important information in considering what modifications could be implemented in the laboratory curriculum and in messaging about the laboratory activities – additionally on how prepared students feel to succeed at college work, how the pandemic has impacted their preparedness for learning, and what we can do to support student learning in chemistry can shape messaging on the first day and for subsequent activities in the course. An initial course survey that sought to highlight these student experiences and perspectives will be discussed along with the impact on course messaging and structure. </p> <p><br></p> Glycobiology Higher education Education assessment and evaluation Learning sciences Other education not elsewhere classified Public health not elsewhere classified Carbohydrates Glycosidic bonds COVID-19 glycoscience Glycoscience Education Higher Education COVID-19 Pandemic Laboratory Visualizations Representations representations in learning Fischer Haworth Fischer projection formulas Fischer projections Haworth projections Glucose Fructose Alpha bond Beta bond Sugar molecules biochemistry education Biochemistry general chemistry laboratory general chemistry General chemistry education curriculum distance learning students distance learning laboratories distance learning technologies Self instruction student centered learning Student centered teaching representational competence representational competencies

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