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  • protein
  • Similar to the regulatory function of this protein in E. coli , five aromatic-pathway genes ( aroF-tyrA , aroP, aroL , and tyrP ) were significantly reduced upon deletion of the tyrR gene. (frontiersin.org)
  • histidine
  • Two genes ( glnL and glnG ) that encode sensory histidine kinase and regulator in a two-component regulatory system involved in nitrogen assimilation were downregulated in the tyrR mutant. (frontiersin.org)
  • Hydrogen
  • The basic structure of all amino acids consists of a carboxyl group, an amino group and a hydrogen atom bonded to a carbon called the alpha carbon (Baldwin, 2003). (studymode.com)
  • molecules
  • Testing this possibility will require flying other spacecraft through the plumes with analytical devices able to detect molecules more closely associated with life, such as amino acids. (separationsnow.com)
  • hydrochloric
  • If a strong acid such as hydrochloric acid (HCl) is added to an amino acid solution, the HCl will donate a proton to carboxylate group to form the carboxyl acid group and therefore, make the solution acidic. (studymode.com)
  • The mixture of nitric and hydrochloric acids was known as aqua regia (royal water), celebrated for its ability to dissolve gold, the king of metals. (wikipedia.org)
  • bacterial
  • Uncharacterized homologues of this system were identified in 33 diverse bacterial species representing 6 different phyla, 21 of which are associated with human disease. (asm.org)
  • ubiquitous
  • We have recently identified another member of this family as responsible for classical amino acid transport System N. Unlike the virtually ubiquitous Systems A, ASC, and L, System N appears more tissue-specific and mediates the uptake specifically of glutamine, histidine, and asparagine ( 25 ). (pnas.org)
  • Mitochondrial branched-chain amino acid aminotransferases are the more ubiquitous of the two isoforms, present in all tissues in the mitochondria of the cell. (wikipedia.org)
  • proton
  • These observations, in conjunction with structural information, identify a working model for pH-induced activation of AdiC in which a closed conformation is disrupted by cation-π interactions between proton and the aromatic side chain of Tyr74. (nih.gov)
  • The System A transporter (SA1) and SN1 share many functional characteristics, including a marked sensitivity to low pH, but, unlike SN1, SA1 does not mediate proton exchange. (pnas.org)
  • Consistent with this sensitivity, we found that the System N transporter (SN1) mediates proton exchange as well as Na + cotransport ( 26 ). (pnas.org)
  • For example, in a titration of an amino acid with an acid, the pk1 will be reached when the (-COO) group gains its proton. (studymode.com)
  • Studies indicate that the amino acid residue His419, located on the domain between TMD X and XI of rat VMAT1, plays a role in energy coupling to the amine transport by assisting the first proton-dependent conformational change. (wikipedia.org)
  • nitric acid
  • Somewhat stronger oxidation by dilute nitric acid gave the diacid, glucaric acid, supporting the proposal of a six-carbon chain. (msu.edu)
  • The name nitrogène was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790, when it was found that nitrogen was present in nitric acid and nitrates. (wikipedia.org)
  • vicinal
  • Glucose and other saccharides are extensively cleaved by periodic acid, thanks to the abundance of vicinal diol moieties in their structure. (msu.edu)
  • molecule
  • A molecule that displays both acidic and basic properties is called a zwitterion (Clark, 2004). (studymode.com)
  • Hot hydriodic acid (HI) was often used to reductively remove oxygen functional groups from a molecule, and in the case of glucose this treatment gave hexane (in low yield). (msu.edu)
  • Scientists
  • Scientists at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, led by Peter Willis , have already developed a microchip electrophoresis device for identifying amino acids on alien planets, which could do the job (see Automatic alien amino acid analysis ). (separationsnow.com)
  • basic
  • Any such extraction would thus need to be fairly basic, and so Willis and his team decided to see whether amino acids could simply be washed out of a silica aerogel using some kind of solvent. (separationsnow.com)
  • Between them, the 10 amino acids came from the five main groups - aromatic, acidic, basic, polar and nonpolar - to see whether their differing chemical properties would affect the extraction. (separationsnow.com)
  • They found that some of solvents struggled to extract the basic amino acids, which become positively charged at certain pHs and so stuck to the negatively charged aerogel. (separationsnow.com)
  • Important basic anatomic and transport mechanisms are presented, followed by current theories on transport of respiratory gases, macronutrients and micronutrients, and waste products. (glowm.com)
  • carrier-mediated
  • 17 18 19 20 A few reports about the presence of carrier-mediated nutrient transport systems on the cornea are available, but most of them are believed to be present on the corneal endothelium. (arvojournals.org)
  • 2. These processes are carrier mediated , discriminating between natural, L amino acids and D-amino acids, require energy (from the Na + gradient, Na-K ATPase) and physiologic temperatures . (gravitywaves.com)
  • gene
  • Multiple hormones increase System A function acutely through changes in the driving force for transport as well as through longer-term changes in gene expression. (pnas.org)
  • sensitivity
  • Transport by System N also depends on Na + but shows a striking sensitivity to inhibition by low external pH. (pnas.org)
  • A Δ 1651 - 1656 deletion strain had an iron-sensitive phenotype, consistent with a previously characterized Δ p19 mutant, and showed reduced growth in acidic medium, increased sensitivity to streptomycin, and higher resistance to H 2 O 2 stress. (asm.org)