Práctica de la reacción de los aminoácidos azufrados: un análisis cualitativo

Roger Alberto Rabelo Florez; Mairuth Escobar Ruiz; Selene Bravo Pérez; Neydis Karina Bastidas Gomez; Ashley Carolina Contreras Obando; Luz Elsy Pérez Ruiz; James Duvan Leon Rangel; Jean Carlos Rodríguez Fuentes; Evelyn Florez Paniza; Yeraldin Amparo Caamaño Cadena; Dayana Andrea Duran Pacheco; Edhisson Navarro Guerrero; Milena Cuellar Meneses; Alexandra Rosmery Sanjuan Arias; Vicky Consuelo Caycedo Rodriguez; Alejandra Sofia Hernandez Molina; Luisa Alejandra Martinez Dominguez; Karol Yireth Barrera Paternina; Enna Luz Pallares Torres; Keren Darley Mármol Ramos

doi:10.22490/26194759.12029

Vol. 10 No. 1 (2027): Vol.10.Núm.1.(2027).

Published 2026-11-15

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Short articles

Reaction of sulfur-containing amino acids: a qualitative analysis

DOI: https://doi.org/10.22490/26194759.12029

Roger Alberto Rabelo Florez National Open and Distance University (UNAD)

Mairuth Escobar Ruiz National Open and Distance University (UNAD)

Selene Bravo Pérez National Open and Distance University (UNAD)

Neydis Karina Bastidas Gomez National Open and Distance University (UNAD)

Ashley Carolina Contreras Obando National Open and Distance University (UNAD)

Luz Elsy Pérez Ruiz National Open and Distance University (UNAD)

James Duvan Leon Rangel National Open and Distance University (UNAD)

Jean Carlos Rodríguez Fuentes National Open and Distance University (UNAD)

Evelyn Florez Paniza National Open and Distance University (UNAD)

Yeraldin Amparo Caamaño Cadena National Open and Distance University (UNAD)

Dayana Andrea Duran Pacheco National Open and Distance University (UNAD)

Edhisson Navarro Guerrero National Open and Distance University (UNAD)

Milena Cuellar Meneses National Open and Distance University (UNAD)

Alexandra Rosmery Sanjuan Arias National Open and Distance University (UNAD)

Vicky Consuelo Caycedo Rodriguez National Open and Distance University (UNAD)

Alejandra Sofia Hernandez Molina National Open and Distance University (UNAD)

Luisa Alejandra Martinez Dominguez National Open and Distance University (UNAD)

Karol Yireth Barrera Paternina National Open and Distance University (UNAD)

Enna Luz Pallares Torres National Open and Distance University (UNAD)

Keren Darley Mármol Ramos National Open and Distance University (UNAD)

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Abstract
References

Introduction: The sulfur-containing amino acid test is an assay in which 20% NaOH provides a basic medium that facilitates the release of sulfur present in cysteine, cystine, and methionine. In the presence of heat, this sulfur converts into sodium sulfide, which then reacts with lead acetate to yield black lead sulfide. Objective: This study aimed to identify the presence of sulfur-containing amino acids in seven biological samples. Methodology: Seven properly labeled test tubes were used. A volume of 2 mL of 20% sodium hydroxide solution was added to each, followed by 10 drops of 5% lead acetate solution. Subsequently, the tubes were placed in a boiling water bath. Results: Tube 1 served as a negative control. Tubes 2 and 3 showed no reaction. Tube 4, containing wheat flour, presented a positive reaction showing a faint blackish color. Meanwhile, tubes 5, 6, and 7 showed a positive reaction with an intense black color. Discussion: The negative results in tubes 1, 2, and 3 are due to the absence of proteins. Conversely, the presence of proteins within the biological samples in the remaining tubes accounts for the positive test results. Conclusion: The laboratory's objective was achieved, as the qualitative test for sulfur-containing amino acids successfully detected protein monomers containing sulfur in their chemical structure across the evaluated biological samples.

keywords: Sulfur-containing amino acids, Cysteine, Methionine, Proteins, Sodium hydroxide, Lead acetate

Attia, Y. A., Al-Harthi, M. A., Korish, M. A., & Shiboob, M. H. (2020). Protein and Amino Acid Content in Four Brands of Commercial Table Eggs in Retail Markets in Relation to Human Requirements. Animals : An Open Access Journal from MDPI, 10(3). https://doi.org/10.3390/ani10030406 DOI: https://doi.org/10.3390/ani10030406

Bruckmaier, R., & Zinn, S. (2023). From the Editors: “Mammalian milk: The elixir of life from maternal care to modern dairy production.” Animal Frontiers, 13(3), 3–4. https://doi.org/10.1093/af/vfad035 DOI: https://doi.org/10.1093/af/vfad035

Buchmueller, L. C., Wunderle, C., Laager, R., Bernasconi, L., Neyer, P. J., Tribolet, P., Stanga, Z., Mueller, B., & Schuetz, P. (2024). Association of phenylalanine and tyrosine metabolism with mortality and response to nutritional support among patients at nutritional risk: a secondary analysis of the randomized clinical trial EFFORT. Frontiers in Nutrition, 11, 1451081. https://doi.org/10.3389/fnut.2024.1451081 DOI: https://doi.org/10.3389/fnut.2024.1451081

Cantarero-Aparicio, M. Á., García-Infante, M., Álvarez, C., Polvillo, O., Perea, J. M., & Horcada, A. (2025). Nutrient Composition of Autochthonous Beef from Southwest Spain. Foods (Basel, Switzerland), 14(22). https://doi.org/10.3390/foods14223961 DOI: https://doi.org/10.3390/foods14223961

Cao, X., Guo, Y., Guo, Z., Liu, Y., Dou, Y., & Xue, L. (2025). One-carbon metabolism in cancer: moonlighting functions of metabolic enzymes and anti-tumor therapy. Cancer and Metastasis Reviews, 44(4), 91. https://doi.org/10.1007/s10555-025-10308-9 DOI: https://doi.org/10.1007/s10555-025-10308-9

Cha, J.-H., Kim, D.-H., Choi, S.-J., Koo, W.-T., & Kim, I.-D. (2018). Sub-Parts-per-Million Hydrogen Sulfide Colorimetric Sensor: Lead Acetate Anchored Nanofibers toward Halitosis Diagnosis. Analytical Chemistry, 90(15), 8769–8775. https://doi.org/10.1021/acs.analchem.8b01273 DOI: https://doi.org/10.1021/acs.analchem.8b01273

Choudhury, F. K., & DeNicola, G. M. (2026). Best practices for cysteine analysis. Ferroptosis and Oxidative Stress, 2. https://doi.org/10.70401/fos.2025.0010 DOI: https://doi.org/10.70401/fos.2025.0010

Cobbinah-Sam, E., & Ekaette, I. (2026). Thermal processing-driven functional transformations of egg components: Albumen and yolk. Food Research International (Ottawa, Ont.), 224, 117929. https://doi.org/10.1016/j.foodres.2025.117929 DOI: https://doi.org/10.1016/j.foodres.2025.117929

Kareem, M. A. (2020). Experiment-6 Qualitative Tests for Amino Acids and Proteins [Indira Gandhi National Open University, New Delhi]. http://egyankosh.ac.in//handle/123456789/68528

Khalid, A., Hameed, A., & Tahir, M. F. (2023). Wheat quality: A review on chemical composition, nutritional attributes, grain anatomy, types, classification, and function of seed storage proteins in bread making quality. Frontiers in Nutrition, 10, 1053196. https://doi.org/10.3389/fnut.2023.1053196 DOI: https://doi.org/10.3389/fnut.2023.1053196

Landi, N., Ragucci, S., & Di Maro, A. (2021). Amino Acid Composition of Milk from Cow, Sheep and Goat Raised in Ailano and Valle Agricola, Two Localities of “Alto Casertano” (Campania Region). Foods (Basel, Switzerland), 10(10). https://doi.org/10.3390/foods10102431 DOI: https://doi.org/10.3390/foods10102431

Leal Afanador, J. A. (2023). Trabajo inteligente productivo. https://libros.unad.edu.co/index.php/selloeditorial/catalog/book/247 DOI: https://doi.org/10.22490/9789584975096

Li, X., & Liu, S.-Q. (2022). Effect of heat treatment on amino acids and volatile compounds of enzymatic pork trimmings hydrolysate supplemented with xylose and cysteine. Food Bioscience, 46(101538), 101538. https://doi.org/10.1016/j.fbio.2021.101538 DOI: https://doi.org/10.1016/j.fbio.2021.101538

National Center for Biotechnology Information. (2026a). Lead acetate (Pb3(AcO)2(OH)4). Lead Acetate (Pb3(AcO)2(OH)4) (compound). https://pubchem.ncbi.nlm.nih.gov/compound/5284406

National Center for Biotechnology Information. (2026b). Sodium Hydroxide. Sodium Hydroxide (compound). https://pubchem.ncbi.nlm.nih.gov/compound/14798

Ngom, R. V., de Paul Ndzana, V., Bohounbele, D., Houli, V., Oumara, B., & Pagnah, A. Z. (2022). Nutritional Quality of Meat from Cattle Breed in Livestock Production Area of Cameroon. Open Journal of Animal Sciences, 12(3), 467–483. https://doi.org/10.4236/ojas.2022.123035 DOI: https://doi.org/10.4236/ojas.2022.123035

Nurliyani, Abidin, M. Z., & Kandarina, I. (2025). Isolation and Characterization of the Microbiological and Physicochemical Qualities, the Protein and Amino Acid Profiles of Fermented Chicken and Duck Egg Ovalbumin. Tropical Animal Science Journal, 48(1), 45–56. https://doi.org/10.5398/tasj.2025.48.1.45 DOI: https://doi.org/10.5398/tasj.2025.48.1.45

Urosevic, D., Knezevic, D., Brankovic, G., Novoselskaya-Dragovich, A., Yu, Kudryavtsev, A., M., Matkovic-Stojsin, M., Micanovic, D., & Zecevic, V. (2023). Protein content and amino acid composition in seed of bread wheat (Triticum aestivum L.). Genetika, 55(1), 301–318. https://doi.org/10.2298/gensr2301301u DOI: https://doi.org/10.2298/GENSR2301301U

Wang, Z. (2026). Amino Acids as Multifunctional Molecules in Plants: From Fundamental Metabolism to Precision Agriculture. Plants (Basel, Switzerland), 15(10). https://doi.org/10.3390/plants15101583 DOI: https://doi.org/10.3390/plants15101583

Zhaskairat, S. Z., Izbasarova, A. I., Igenbaev, A. K., Kardenov, S. A., Kozhamsugirov, K. M., Жасқайрат, Ш. Ж., Ізбасарова, A. I., Игенбаев, А. К., Карденов, С. А., Кожамсугиров, К. М., & Iзбасарова, А. I. (2025). ХИМИЧЕСКИЙ СОСТАВ И ФИЗИКО-ХИМИЧЕСКИЕ ПОКАЗАТЕЛИ МЯСА ШЕИ, СПИНЫ, БЕДЕР ГОВЯДИНЫ И КОНИНЫ. Bulletin of Shakarim University. Technical Sciences, 0(2(18)), 194–200. https://doi.org/10.53360/2788-7995-2025-2(18)-23 DOI: https://doi.org/10.53360/2788-7995-2025-2(18)-23

Zheng, P., Jin, Y., Wei, C., & Xia, C. (2026). Sulfur-Containing Amino Acids: The Conversion Process from Product to Substrate. International Journal of Molecular Sciences, 27(11). https://doi.org/10.3390/ijms27114771 DOI: https://doi.org/10.3390/ijms27114771

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How to Cite

Rabelo Florez, R. A., Escobar Ruiz, M., Bravo Pérez, S., Bastidas Gomez, N. K., Contreras Obando, A. C., Pérez Ruiz, L. E., Leon Rangel, J. D., Rodríguez Fuentes, J. C., Florez Paniza, E., Caamaño Cadena, Y. A., Duran Pacheco, D. A., Navarro Guerrero, E., Cuellar Meneses, M., Sanjuan Arias, A. R., Caycedo Rodriguez, V. C., Hernandez Molina, A. S., Martinez Dominguez, L. A., Barrera Paternina, K. Y., Pallares Torres, E. L., & Mármol Ramos, K. D. (2026). Reaction of sulfur-containing amino acids: a qualitative analysis. Biociencias, 10(1), 71-79. https://doi.org/10.22490/26194759.12029

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