Amino Acid Functions PDF
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Uploaded by yvesss
Ayura 2027
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Summary
This document provides a detailed overview of the functions of various amino acids. It explores how amino acids like glycine contribute to processes like bile salt formation, and how others, like alanine, are involved in gluconeogenesis. The document also discusses other critical functions of these amino acids within biological systems, including the impact on cellular processes and neurotransmission.
Full Transcript
1. Glycine: Bile Salts (e.g., glycocholate): Glycine conjugates with bile acids (like cholic acid) to form bile salts, aiding fat digestion and absorption. Hippuric Acid: Formed when glycine combines with benzoic acid in a detoxification reaction, used as a liver function test. Creatine:...
1. Glycine: Bile Salts (e.g., glycocholate): Glycine conjugates with bile acids (like cholic acid) to form bile salts, aiding fat digestion and absorption. Hippuric Acid: Formed when glycine combines with benzoic acid in a detoxification reaction, used as a liver function test. Creatine: Along with arginine and methionine, glycine contributes to creatine synthesis, vital for muscle energy storage. Heme: Glycine and succinyl-CoA form δ-aminolevulinic acid, a precursor for heme in hemoglobin and myoglobin. Purines: Glycine supplies atoms for building the purine ring, essential in DNA and RNA synthesis. Glutathione: With cysteine and glutamate, glycine forms glutathione, a major antioxidant in cells. 2. Alanine: Glucose (via Gluconeogenesis): Alanine can be converted to pyruvate, then glucose, especially during fasting. Coenzyme A (CoA): Alanine contributes to the thioethanolamine portion of CoA, a cofactor in metabolic reactions. Carnosine and Anserine: These β-alanyl dipeptides (formed with histidine) function as antioxidants and buffer muscle pH during exercise. Lactate (via Cori Cycle): Under anaerobic conditions, alanine is indirectly converted to lactate in muscles. 3. Serine, Threonine, and Tyrosine: Phosphorylated Derivatives: Phosphorylated forms (e.g., phosphoserine, phosphotyrosine) regulate enzyme activities in cell signaling. Phosphatidylserine: Derived from serine, it is crucial in cell membranes and signal transduction. Sphingolipids: Serine and threonine are precursors for sphingolipids, essential in neural tissue structure. 4. Methionine: S-adenosylmethionine (SAM): A universal methyl donor, SAM is essential for methylation of DNA, proteins, and neurotransmitters. Polyamines (e.g., spermidine, spermine): Support cell growth, stabilize DNA, and provide cellular protection from oxidative stress. Epinephrine: Methylation of norepinephrine forms epinephrine (adrenaline), important in the "fight-or-flight" response. Creatine Phosphate: Stores high-energy phosphate bonds, aiding in ATP regeneration in muscles. Choline: Essential for brain health as a neurotransmitter precursor and membrane component. Carnitine: Transports fatty acids into mitochondria for energy production. 5. Cysteine: Coenzyme A (CoA): Cysteine provides the thiol (-SH) group in CoA, essential for fatty acid and acyl group activation. Taurine: Conjugates with bile acids to form bile salts, aiding fat absorption. Cystine: Cystine, formed from two cysteine molecules via a disulfide bond, stabilizes protein structures. Mercaptopyruvate: A derivative involved in sulfur metabolism, playing a role in antioxidant pathways. 6. Histidine: Histamine: Formed by decarboxylation, histamine mediates allergic responses and regulates stomach acid. Ergothioneine, Carnosine, Anserine: Antioxidants that protect tissues, especially in muscles and the brain. Urocanic Acid: A skin product of histidine that may provide UV protection. 7. Arginine: Nitric Oxide (NO): A vasodilator and signaling molecule critical for blood pressure regulation and neurotransmission. Creatine: Arginine provides the amidine group, forming creatine for muscle energy storage. Polyamines (Putrescine, Spermidine, Spermine): Support DNA stability, cellular growth, and organelle stability. Ornithine and Citrulline (in the Urea Cycle): Arginine converts to ornithine and citrulline, crucial for nitrogen excretion. 8. Tyrosine: Thyroid Hormones (T3 and T4): Regulate metabolism and are synthesized from tyrosine. Melanin: Pigment derived from tyrosine, responsible for skin, hair, and eye color. Catecholamines (Dopamine, Norepinephrine, Epinephrine): Tyrosine is a precursor to these neurotransmitters, which impact mood, stress response, and other physiological functions. L-DOPA: An intermediate in dopamine synthesis, used in neurological functions. 9. Glutamate: Gamma-aminobutyric Acid (GABA): An inhibitory neurotransmitter, reducing neural excitability and promoting relaxation. Proline: Glutamate is a precursor to proline, a major component in collagen structure. Glutamine: Derived from glutamate, it serves as a nitrogen donor for nucleotide synthesis. 10. Tryptophan: Serotonin: A neurotransmitter that regulates mood, sleep, and appetite and also contributes to smooth muscle function. Melatonin: Derived from serotonin, melatonin regulates circadian rhythms and induces sleep. Niacin (Vitamin B3): Tryptophan can convert to niacin, essential for energy production and DNA repair. Kynurenine Pathway Products: Breakdown of tryptophan through this pathway produces immune-signaling metabolites. Indoles (via Gut Microbiota): Tryptophan conversion to indoles in the gut impacts gut health and immune signaling.
