Other Biochemistry, Biophysics, and Structural Biology Commons^™

Raman Spectroscopy For Rapid Quantification Of Macronutrients In Heirloom Beans, K. Chandler Williams

Graduate Theses, Dissertations, and Problem Reports (ETD)

Quantification of macronutrients in food requires a large investment in facilities and instrumentation as well as ongoing expenses of labor, reagents, and hazardous waste disposal. These costs pose a significant barrier to determining macronutrient quantities in the thousands of uncharacterized landrace and heirloom crops and discourage traditional crop breeding projects from ensuring that their selected crops maintain desirable macronutrient profiles in addition to target agronomic traits. Our objective was to test whether a hand-held Raman spectrometer—a technology which has found use in plant disease diagnostics but remains largely overlooked in nutrient quantification-- could provide a feasible means for quantifying the …

Du Undergraduate Showcase: Research, Scholarship, And Creative Works, Caitlyn Aldersea, Justin Bravo, Sam Allen, Anna Block, Connor Block, Emma Buechler, Maria De Los Angeles Bustillos, Arianna Carlson, William Christensen, Olivia Kachulis, Noah Craver, Kate Dillon, Muskan Fatima, Angel Fernandes, Emma Finch, Colleen Cassidy, Amy Fishman, Andrea Francis, Stacia Fritz, Simran Gill, Emma Gries, Rylie Hansen, Shannon Powers, Jacqueline Martinez, Zachary Harker, Ashley Hasty, Mykaela Tanino-Springsteen, Kathleen Hopps, Adelaide Kerenick, Colin Kleckner, Ci Koehring, Elijah Kruger, Braden Krumholz, Maddie Leake, Lyneé Alves, Seraphina Loukas, Yatzari Lozano Vazquez, Haley Maki, Emily Martinez, Sierra Mckinney, Audrey Mitchell, Kipling Newman, Audrey Ng, Megan Lucyshyn, Andrew Nguyen, Stevie Ostman, Casandra Pearson, Alexandra Penney, Julia Gielczynski, Tyler Ball, Anna Rini, Christina Rorres, Simon Ruland, Helayna Schafer, Emma Sellers, Sarah Schuller, Claire Shaver, Kevin Summers, Isabella Shaw, Madison Sinar, Claudia Pena, Apshara Siwakoti, Carter Sorensen, Madi Sousa, Anna Sparling, Alexandra Revier, Brandon Thierry, Dylan Tyree, Maggie Williams, Lauren Wols

DU Undergraduate Research Journal Archive

DU Undergraduate Showcase: Research, Scholarship, and Creative Works

Investigation Of The Binding Domain Interfaces Of The C-Terminus Of The Albino3 Insertase And The 43kda Chloroplast Signal Recognition Particle Subunit Via Single Molecule Förster Resonance Energy Transfer, Amanda Tomanek

Chemistry & Biochemistry Undergraduate Honors Theses

Fluorescent labeling is a technique used for visualizing functional groups contained in biomolecules by fluorescence imaging. This technique was used in this project to analyze post-translational targeting of light-harvesting chlorophyll-binding proteins (LHCP), which are the core complexes that harvest sunlight to drive photosynthetic electron transfer. This protein is synthesized in the cytosol and post-translationally targeted to the stroma of chloroplasts. CpSRP43 is a signal recognition particle (SRP) subunit unique to chloroplasts, which has been shown to interact with the stroma-soluble C-terminus of the thylakoid-bound Albino3 insertase (Alb3-Cterm). In the chloroplast stroma, targeting to thylakoids is performed via the cpSRP pathway …

Computational Prediction Of Mutagenesis In Glycine Max Rubisco Activase Monomer For Increased Thermal Stability, Catherine B. Emanuel, Hamza Haq '21, Vasanth Ramesh '21, Jaden Wang '21, Angela Ahrendt, Sarah Stainbrook

Student Publications & Research

No abstract provided.

Arabinose Substitution Effect On Xylan Rigidity And Self-Aggregation, Utsab Shrestha, Sydney Smith, Sai Venkatesh Pingali, Hui Yang, Mai Zahran, Llyod Breunig, Liza Wilson, Daniel Cosgrove, Hugh O'Neill, Loukas Petridis

Publications and Research

Substituted xylans play an important role in the structure and mechanics of the primary cell wall of plants. Arabinoxylans (AX) consist of a xylose backbone substituted with arabinose, while glucuronoarabinoxylans (GAX) also contain glucuronic acid substitutions and ferulic acid esters on some of the arabinoses. We provide a molecular-level description on the dependence of xylan conformational, selfaggregation properties and binding to cellulose on the degree of arabinose substitution. Molecular dynamics simulations reveal fully solubilized xylans with a low degree of arabinose substitution (lsAX) to be stiffer than their highly substituted (hsAX) counterparts. Small-angle neutron scattering experiments indicate that both wild-type …

Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, Caitlyn R. Witkowski, Johan W. H. Weijers, Brian S. Blais, Stefan Schouten, Jaap S. Sinninghe Damsté

Science and Technology Department Faculty Journal Articles

Past changes in the atmospheric concentration of carbon dioxide (PCO2) have had a major impact on earth system dynamics; yet, reconstructing secular trends of past PCO2 remains a prevalent challenge in paleoclimate studies. The current long-term PCO2reconstructions rely largely on the compilation of many different proxies, often with discrepancies among proxies, particularly for periods older than 100 million years (Ma). Here, we reconstructed Phanerozoic PCO2 from a single proxy: the stable carbon isotopic fractionation associated with photosynthesis (Ɛp) that increases as PCO2 increases. This concept has been widely applied to alkenones, but here, we …

Lipid Transport Required To Make Lipids Of Photosynthetic Membranes, Evan Labrant, Allison C. Barnes, Rebecca Roston

Department of Biochemistry: Faculty Publications

Photosynthetic membranes provide much of the usable energy for life on earth. To produce photosynthetic membrane lipids, multiple transport steps are required, including fatty acid export from the chloroplast stroma to the endoplasmic reticulum, and lipid transport from the endoplasmic reticulum to the chloroplast envelope membranes. Transport of hydrophobic molecules through aqueous space is energetically unfavorable and must be catalyzed by dedicated enzymes, frequently on specialized membrane structures. Here, we review photosynthetic membrane lipid transport to the chloroplast in the context of photosynthetic membrane lipid synthesis. We independently consider the identity of transported lipids, the proteinaceous transport components, and membrane …

Binding Of Maize Necrotic Streak Virus (Mnesv) 3’ I-Shaped Structure (3’ Iss) To Eukaryotic Translation Factors (Eifs) And Implication In Eif4f Mediated Translation Initiation, Qiao Liu

Dissertations, Theses, and Capstone Projects

5' m⁷GpppN cap and the 3' poly adenosine (A) tail of eukaryotic mRNAs are key elements for recruiting translation initiation machinery in canonical translation initiation. Unlike host mRNAs, many viruses lack these elements and yet they are translated efficiently. Plant viruses, in particular, have complex structures within their untranslated regions (UTR) that allow them to bypass some cellular translation control steps. In Maize necrotic streak virus (MNeSV) 3' UTR, an I-Shaped RNA Structure (ISS) has been reported to mediate the virus translation initiation progress. 3’ ISS binding with eIF4F has been shown to facilitate translation. 5’ -3’ kissing …

Hydrogenation Of Organic Matter As A Terminal Electron Sink Sustains High Co2:Ch4 Production Ratios During Anaerobic Decomposition, Rachel M. Wilson, Malak M. Tfaily, Virginia I. Rich, Jason K. Keller, Scott D. Bridgham, Cassandra Medvedeff Zalman, Laura Meredith, Paul J. Hanson, Mark Hines, Laurel Pfeifer-Meister, Scott R. Saleska, Patrick Crill, William T. Cooper, Jeff P. Chanton, Joel E. Kostka

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Once inorganic electron acceptors are depleted, organic matter in anoxic environments decomposes by hydrolysis, fermentation, and methanogenesis, requiring syntrophic interactions between microorganisms to achieve energetic favorability. In this classic anaerobic food chain, methanogenesis represents the terminal electron accepting (TEA) process, ultimately producing equimolar CO₂ and CH₄ for each molecule of organic matter degraded. However, CO₂:CH₄ production in Sphagnum-derived, mineral-poor, cellulosic peat often substantially exceeds this 1:1 ratio, even in the absence of measureable inorganic TEAs. Since the oxidation state of C in both cellulose-derived organic matter and acetate is 0, and CO₂ has …

Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera

Honors Undergraduate Theses

In this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 μm in the lateral and 3.6 μm in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation while providing a strong signal from the contrast generated by the attenuation of propagating light due to absorption. This enables spatially resolved measurements of single …

Methane Fluxes And Porewater Dissolved Organic Carbon Dynamics From Different Peatlands Types In The Pastaza-Marañon Basin Of The Peruvian Amazon., Jhon Del Aguila-Pasquel

Dissertations, Master's Theses and Master's Reports

Relevant components of the carbon budget such as methane fluxes and porewater dissolved organic carbon (DOC) are poorly characterized in the Peruvian Pastaza Marañon basin (PMB). PMB is associated with a tropospheric hotspot for methane and therefore it may represent a significant methane source. We aimed to quantify the magnitude of CH₄ fluxes and porewater DOC; and to determine their predictors across different peatland types in the PMB (open peatland, palm swamp, and pole forest). The study was conducted in two peatland sites covering the three main vegetation types in PMB. We collected gas and water samples using chamber-based …

Fishing For A Sustainable Future: Aquaponics As A Method Of Food Production, Richard Ramsundar

Student Theses 2015-Present

This thesis compares and explains the advantages aquaponics farming has over modern industrial intensive farming. Through a comparison natural capital usage, conservation, recycling and cost, the thesis advocates for the expansion of aquaponics usage in urban settings. The thesis also explains the history of intensive farming and aquaponics in America, the science of how aquaponics operates, the economic and environmental costs of modern intensive farming versus aquaponics farming, and the social implications of aquaponics. Lastly, I propose a policy that reallocates farm subsidies by modifying the Farm Bill. Then I propose policies that support creating a new standard of farm …

Overexpression Of Patatin-Related Phospholipase Aiiiβ Altered The Content And Composition Of Sphingolipids In Arabidopsis, Maoyin Li, Jennifer E. Markham, Xuemin Wang

Department of Biochemistry: Faculty Publications

In plants, fatty acids are primarily synthesized in plastids and then transported to the endoplasmic reticulum (ER) for synthesis of most of the complex membrane lipids, including glycerolipids and sphingolipids. The first step of sphingolipid synthesis, which uses a fatty acid and a serine as substrates, is critical for sphingolipid homeostasis; its disruption leads to an altered plant growth. Phospholipase As have been implicated in the trafficking of fatty acids from plastids to the ER. Previously, we found that overexpression of a patatin-related phospholipase, pPLAIIIβ, resulted in a smaller plant size and altered anisotropic cell expansion. Here, we determined the …

Arabidopsis Accelerated Cell Death 11, Acd11, Is A Ceramide-1-Phosphate Transfer Protein And Intermediary Regulator Of Phytoceramide Levels, Dhirendra K. Simanshu, Xiuhong Zhai, David Munch, Daniel Hofius, Jennifer E. Markham, Jacek Bielawski, Alicja Bielawska, Lucy Malinina, Julian G. Molotkovsky, John W. Mundy, Dinshaw J. Patel, Rhoderick E. Brown

Department of Biochemistry: Faculty Publications

The accelerated cell death 11 (acd11) mutant of Arabidopsis provides a genetic model for studying immune response activation and localized cellular suicide that halt pathogen spread during infection in plants. Here, we elucidate ACD11 structure and function and show that acd11 disruption dramatically alters the in vivo balance of sphingolipid mediators that regulate eukaryotic-programmed cell death. In acd11 mutants, normally low ceramide-1- phosphate (C1P) levels become elevated, but the relatively abundant cell death inducer phytoceramide rises acutely. ACD11 exhibits selective intermembrane transfer of C1P and phyto-C1P. Crystal structures establish C1P binding via a surface-localized, phosphate headgroup recognition center …

Connections Between Sphingosine Kinase And Phospholipase D In The Abscisic Acid Signaling Pathway In Arabidopsis, Liang Guo, Girish Mishra, Jennifer E. Markham, Maoyin Li, Amanda Tawfall, Ruth Welti, Xuemin Wang

Department of Biochemistry: Faculty Publications

Background: Sphingosine kinase (SPHK) and phospholipaseD(PLD) produce different lipid mediators involved in abscisic acid (ABA) response.

Results: Ablation of SPHKs and PLDα1 attenuates ABA-induced production of LCBPs and PA. Phyto-S1P closes stomata in sphk1, sphk2, but not in pldα1, whereas PA closes stomata in all mutants.

Conclusion: SPHK acts upstream of PLDα1, whereas PLDα1 promotes SPHK.

Significance: The roles of lipid messengers in the ABA signaling pathway are clarified.

Letter From The Dean, Lalit Verma

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.