Matching Items (10)
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- All Subjects: Photosynthesis
- Creators: School of Molecular Sciences
Description
In oxygenic photosynthesis, conversion of solar energy to chemical energy is catalyzed by the<br/>pigment-protein complexes Photosystem II (PSII) and Photosystem I (PSI) embedded within the<br/>thylakoid membrane of photoautotrophs. The function of these pigment-protein complexes are<br/>conserved between all photoautotrophs, however, the oligomeric structure, as well as the<br/>spectroscopic properties of the PSI complex, differ. In early evolving photoautotrophs, PSI<br/>exists in a trimeric organization, but in later evolving species this was lost and PSI exists solely<br/>as a monomer. While the reasons for a change in oligomerization are not fully understood, one<br/>of the 11 subunits within cyanobacterial PSI, PsaL, is thought to be involved in trimerization<br/>through the coordination of a calcium ion in an adjacent monomer. Recently published<br/>structures have demonstrated that PSI complexes are capable of trimerization without<br/>coordinating the calcium ion within PsaL.<br/>5 Here we explore the role the calcium ion plays in both<br/>the oligomeric and spectroscopic properties in PSI isolated from Synechocystis sp. PCC 6803.
ContributorsVanlandingham, Jackson R (Author) / Mazor, Yuval (Thesis director) / Mills, Jeremy (Committee member) / School of Life Sciences (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
This thesis examines the emerging significance of bubble tea as a part of a larger cultural identity of second generation Asian-Americans and how it has transformed between generations in the United States. From a seemingly simple drink to the global phenomenon that has shifted in connotation to a highly sophisticated crafted drink that has led to the “third-wave coffee shops” and a “third place” for many Asian-Americans today. Specifically, I analyze the ways that bubble tea has become almost synonymous with the Asian-American youth culture due to a shift in globalization, migration, and cultural power. Through a qualitative analysis as well as a social observation of the audience and targeted groups of consumers as each local shop, I will examine the influence of bubble tea. With this work, I show how bubble tea reflects a sense of “home” and an identity rooted in immigration to Asian-American pop culture today.
ContributorsVo, Crystal H (Author) / Ingram-Waters, Mary (Thesis director) / Popova, Laura (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Coral reefs are diverse marine ecosystems, where reef building corals provide both the structure of the habitat as well as the primary production through their symbiotic algae, and alongside algae living on the reef itself, are the basis of the food web of the reef. In this way, coral reefs are the ocean's "forests" and are estimated to support 25% of all marine species. However, due to the large size of a coral reef, the relative inaccessibility and the reliance on in situ surveying methods, our current understanding of reefs is spatially limited. Understanding coral reefs from a more spatially complete perspective will offer insight into the ecological factors that contribute to coral reef vitality. This has become a priority in recent years due to the rapid decline of coral reefs caused by mass bleaching. Despite this urgency, being able to assess the entirety of a coral reef is physically difficult and this obstacle has not yet been overcome. However, similar difficulties have been addressed in terrestrial ecosystems by using remote sensing methods, which apply hyperspectral imaging to assess large areas of primary producers at high spatial resolutions. Adapting this method of remote spectral sensing to assess coral reefs has been suggested, but in order to quantify primary production via hyper spectral imaging, light-use efficiencies (LUEs) of coral reef communities need to be known. LUEs are estimations of the rate of carbon fixation compared to incident absorbed light. Here, I experimentally determine LUEs and report on several parameters related to LUE, namely net productivity, respiration, and light absorbance for the main primary producers in coral reefs surrounding Bermuda, which consist of algae and coral communities. The derived LUE values fall within typical ranges for LUEs of terrestrial ecosystems, with LUE values for coral averaging 0.022 ± 0.002 mol O2 mol photons-1 day-1 at a water flow rate of 17.5 ± 2 cm s^(-1) and 0.049 ± 0.011 mol O2 mol photons-1 day-1 at a flow rate of 32 ± 4 cm s^(-1) LUE values for algae averaged 0.0335 ± 0.0048 mol O2 mol photons-1 day-1 at a flow rate of 17.5 ± 2 cm s^(-1). These values allow insight into coral reef productivity and opens the door for future remote sensing applications.
ContributorsFlesher, David A (Author) / Neuer, Susanne (Thesis director) / Redding, Kevin (Committee member) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The heliobacteria, a family of anoxygenic phototrophs, are significant to photosynthesis evolution research, as they possess the simplest known photosynthetic apparatus. Although they are photoheterotrophs in the light, the heliobacteria may also grow chemotrophically via pyruvate metabolism in the absence of light. In Heliobacterium modesticaldum, the cytochrome bc complex is responsible for oxidizing menaquinol and reducing cytochrome c553 in the electron flow cycle used for phototrophy. However, there is no known electron acceptor for cytochrome c553 other than the photosynthetic reaction center. Therefore, it was hypothesized that the cytochrome bc complex is necessary for phototrophy, but unnecessary for chemotrophic growth in the dark. Under this hypothesis, a mutant of H. modesticaldum lacking the cytochrome bc complex was predicted to be viable, but non-phototrophic. In this project, a two-step method for CRISPR-based genome editing was used in H. modesticaldum to delete the genes encoding the cytochrome bc complex. Genotypic analysis verified the deletion of the petC, B, D, and A genes encoding the catalytic components of complex. Spectroscopic studies revealed that re-reduction of cytochrome c553 after flash-induced photo-oxidation was ~130 to 190 times slower in the ∆petCBDA mutant compared to wildtype, phenotypically confirming the removal of the cytochrome bc complex. The resulting ∆petCBDA mutant was unable to grow phototrophically, instead relying on pyruvate metabolism to grow chemotrophically as does wildtype in the dark.
ContributorsLeung, Sabrina (Author) / Redding, Kevin (Thesis director) / Liu, Wei (Committee member) / Vermaas, Wim (Committee member) / School of Molecular Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The Heliobacterial Reaction Center (HbRC) is the simplest Type I Reaction Center (RC) known today. However, upon illumination it has been found to produce menaquinol, and this has led to experiments investigating the function of this reduction scheme. The goal of the experiment was to investigate the mechanisms of menaquinol production through the use of Photosystem II (PSII) herbicides that are known to inhibit the QB quinone site in Type II RCs. Seven herbicides were chosen, and out of all of them terbuthylazine showed the greatest effect on the RC in isolated membranes when Transient Absorption Spectroscopy was used. In addition, terbuthylazine decreased menaquinone reduction to menaquinol by ~72%, slightly more than the reported effect of teburtryn (68%)1. In addition, terbuthylazine significantly impacted growth of whole cells under high light more than terbutryn.
ContributorsOdeh, Ahmad Osameh (Author) / Redding, Kevin (Thesis director) / Woodbury, Neal (Committee member) / Allen, James (Committee member) / School of Molecular Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
We founded an operational startup company and developed a consumable product to sell to ASU students. Our primary objective is the provision of affordable nutritious energy bars to overworked and overwhelmed college students. We aim to support hungry students in efforts to fuel their bodies efficiently and nutritiously; in order to do so, we donate 20% of our profits to charity to support students in debt. Our business won the Business Catalyst Choice Award for having "the most promising business concept" in the Founder's Lab 2022-23 Cohort.
ContributorsPartin, Calvin (Author) / Valandra, Grace (Co-author) / Raghavan, Vishnu (Co-author) / Saxena, Rishi (Co-author) / Byrne, Jared (Thesis director) / Kneer, Danny (Committee member) / Asselyn, Dakota (Committee member) / Gajera, Rajanikant (Committee member) / Barrett, The Honors College (Contributor) / School of Molecular Sciences (Contributor)
Created2023-05
Description
By 2050, feeding the world will require a 70% increase in food production with fewer water resources due to climate change. New strategies are needed to replace current approaches. C3 photosynthesis is inefficient due to photorespiration, but synthetic biology offers a way to increase photosynthetic efficiency and crop yields, such as the tartronyl-CoA (TaCo) pathway. This project assesses the TaCo pathway in the chloroplast of Chlamydomonas reinhardtii and represents a pivotal step toward its practical application in higher plants for use in agriculture and biotechnology.
ContributorsCerna, Gabriella (Author) / Sharma, Priyati (Co-author) / Redding, Kevin (Thesis director) / Bartelle, Benjamin (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Molecular Sciences (Contributor)
Created2024-05
Description
Oral health is influenced by many factors, including diet (Alpert, 2017). However, the assumption arises that unique and ever-changing diets have varying effects on oral health. This project aimed to determine the effect of the Punjabi diet on oral health. Specific goals included understanding components of a general Punjabi diet, as well as the current oral health status for individuals of the Punjabi community, to ultimately determine the correlations between the two variables. It was hypothesized that a diet consisting of foods primarily under the Punjabi diet would have fewer oral health concerns because healthier food items would be consumed. By researching relevant background information to create appropriate survey questions, survey questionnaires were sent to members of the Punjabi population (not just limited to the Punjab geographical region) for completion. From this data, analysis depicts that there is no relationship between the oral health of individuals with the diet they consumed, thus rejecting the initial hypothesis. Similarly, a lack of a relationship was found between the oral health of individuals and their respective oral hygiene habits. These results suggest that the current Punjabi diet may not be as healthy as initially assumed and that there are likely other factors that influence an individual’s oral health, such as genetics, environmental factors such as stress (Kapila, 2021), or other unexplored dietary variables, such as diets high in sugar.
ContributorsKaur, Loveleen (Author) / Cipolla, Karen (Thesis director) / Dhanjal, Sabrina (Committee member) / Savalli, Udo (Committee member) / Barrett, The Honors College (Contributor) / School of Molecular Sciences (Contributor) / Dean, W.P. Carey School of Business (Contributor)
Created2022-05
Description
Chutneys are a form of Indian condiment that can be made in many different flavors and paired with various foods. However, the availability of chutneys in the United States is very limited and many people have not tried them before. With this observation in mind, we founded A2Z Chutneys, which is a business that aims to distribute a variety of organic and locally produced chutneys. Through the Founders Lab program, A2Z Chutneys was created and research was conducted to justify the viability of our business. We were able to gather and interpret data from potential customers, which allowed us to identify a target market. Additionally, time was spent identifying and creating a variety of authentic and unique chutneys that have proven to be desired. This report demonstrates and outlines the feasibility of A2Z Chutneys in providing unique and desirable flavors to the population.
ContributorsPatel, Javin (Author) / Macha, Sankshay (Co-author) / Byrne, Jared (Thesis director) / Patel, Manish (Committee member) / Pierce, John (Committee member) / Barrett, The Honors College (Contributor) / School of Molecular Sciences (Contributor) / School of Politics and Global Studies (Contributor) / School of Life Sciences (Contributor)
Created2023-05
Description
Higher plant Rubisco activase (Rca) is a stromal ATPase responsible for reactivating Rubisco. It is a member of the AAA+ protein superfamily and is thought to assemble into closed-ring hexamers like other AAA+ proteins belonging to the classic clade. Progress towards modeling the interaction between Rca and Rubisco has been slow due to limited structural information on Rca. Previous efforts in the lab were directed towards solving the structure of spinach short-form Rca using X-ray crystallography, given that it had notably high thermostability in the presence of ATP-γS, an ATP analog. However, due to disorder within the crystal lattice, an atomic resolution structure could not be obtained, prompting us to move to negative stain electron microscopy (EM), with our long-term goal being the use of cryo-electron microscopy (cryo-EM) for atomic resolution structure determination. Thus far, we have screened different Rca constructs in the presence of ATP-γS, both the full-length β-isoform and truncations containing only the AAA+ domain. Images collected on preparations of the full-length protein were amorphous, whereas images of the AAA+ domain showed well-defined ring-like assemblies under some conditions. Procedural adjustments, such as the use of previously frozen protein samples, rapid dilution, and minimizing thawing time were shown to improve complex assembly. The presence of Mn2+ was also found to improve hexamer formation over Mg2+. Calculated class averages of the AAA+ Rca construct in the presence of ATP-γS indicated a lack of homogeneity in the assemblies, showing both symmetric and asymmetric hexameric rings. To improve structural homogeneity, we tested buffer conditions containing either ADP alone or different ratios of ATP-γS to ADP, though results did not show a significant improvement in homogeneity. Multiple AAA+ domain preparations were evaluated. Because uniform protein assembly is a major requirement for structure solution by cryo-EM, more work needs to be done on screening biochemical conditions to optimize homogeneity.
ContributorsHernandez, Victoria Joan (Author) / Wachter, Rebekka (Thesis director) / Chiu, Po-Lin (Committee member) / Redding, Kevin (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05