Harpers

INDEX / 683transport, 454–455, 454t, 455txenobiotic cell injury and, 631Proteoglycans, 109, 535, 538, 542–549,542f. See alsoGlycosaminoglycansin bone, 548tcarbohydrates in, 542, 542f, 543fin cartilage, 551, 553disease associations and, 548–549functions of, 547–549, 548tgalactose in synthesis of, 167–169, 170flink trisaccharide in, 518Proteolysisin covalent modification, 76, 76–77, 77fin prochymotrypsin activation, 77, 77fProteome/proteomics, 28–29, 414,636–637, 637–638Prothrombin (factor II), 600t, 601, 602factivation of, 601coumarin drugs affecting, 487, 604in vitamin K deficiency, 487Prothrombinase complex, 601Proton acceptors, bases as, 9Proton donors, acids as, 9Proton pump, respiratory chain complexesas, 96, 96f, 97fProton-translocating transhydrogenase, assource of intramitochondrialNADPH, 99Protons, transport of, by hemoglobin, 44,45fProtoporphyrin, 270, 272fincorporation of iron into, 271–272, 272fProtoporphyrin III, 271, 276fProtoporphyrinogen III, 271, 276fProtoporphyrinogen oxidase, 271, 275f, 276fProvitamin A carotenoids, 482–483Proximal histidine (histidine F8)in oxygen binding, 40, 41freplacement of in hemoglobin M, 46Proximity, catalysis by, 51PrP (prion-related protein), 37PRPPin purine synthesis, 294, 295fin pyrimidine synthesis, 296, 298f, 299PRPP glutamyl amidotransferase, 294, 295fPRPP synthetase, defect in, gout caused by,299Pseudo-Hurler polydystrophy, 532, 546t,547Pseudogenes, 325, 414Psi (ψ) angle, 31, 31fPstI, 399tPstI site, insertion of DNA at, 402, 403fPTA. See Plasma thromboplastin antecedentPTC. See Plasma thromboplastincomponentPteroylglutamic acid. See Folic acidPTH. See Parathyroid hormonePTSs. See Peroxisomal-matrix targetingsequences“Puffs,” polytene chromosome, 318, 318fPulsed-field gel electrophoresis, for geneisolation, 635tPumps, 415in active transport, 427–428, 428fPurification, protein/peptide, 21–24Purine nucleoside phosphorylase deficiency,300Purines/purine nucleotides, 286–290, 286f,289fdietarily nonessential, 293metabolism of, 293–302disorders of, 300gout as, 299uric acid formation and, 299, 299fsynthesis of, 293–294, 294f, 295f, 296f,297fcatalysts in, 293, 294fpyrimidine synthesis coordinated with,299“salvage” reactions in, 294, 295f, 297fultraviolet light absorbed by, 290Puromycin, 372, 372fPutrescine, in polyamine synthesis, 266fPyranose ring structures, 103f, 104Pyridoxal phosphate, 50, 491, 491fin heme synthesis, 270in urea biosynthesis, 243Pyridoxine/pyridoxal/pyridoxamine(vitamin B 6 ), 482t, 491, 491fdeficiency of, 482t, 491xanthurenate excretion in, 258, 258fexcess/toxicity of, 491Pyrimethamine, 494Pyrimidine analogs, in pyrimidinenucleotide biosynthesis, 297Pyrimidines/pyrimidine nucleotides,286–290, 286f, 289fdietarily nonessential, 293metabolism of, 293–302, 301fdiseases caused by cataboliteoverproduction and, 300–301water-soluble metabolites and, 300,301fprecursors of, deficiency of, 300–301synthesis of, 296–299, 298fcatalysts in, 296purine synthesis coordinated with, 299regulation of, 297–299, 298fultraviolet light absorbed by, 290Pyrophosphatase, inorganicin fatty acid activation, 85, 180in glycogen biosynthesis, 145, 146fPyrophosphatefree energy of hydrolysis of, 82tinorganic, 85, 85fPyrrole, 40, 41fPyruvate, 123formation of, in amino acid carbonskeleton catabolism, 250–255,252f, 253foxidation of, 134, 135f, 140–142, 141f,142f, 143t. See also Acetyl-CoA;Glycolysisclinical aspects of, 142–143enzymes in, 156tgluconeogenesis and, 153, 154fPyruvate carboxylase, 133, 134f, 156tin gluconeogenesis regulation, 133, 134f,153, 156tPyruvate dehydrogenase, 134, 135f, 140,141f, 156tdeficiency of, 143regulation of, 141–142, 142facyl-CoA in, 141–142, 142f, 178thiamin diphosphate as coenzyme for,488Pyruvate dehydrogenase complex, 140Pyruvate kinase, 156tdeficiency of, 143, 619gluconeogenesis regulation and, 157in glycolysis, 137–139, 138f, 156tregulation and, 140Q (coenzyme Q/ubiquinone), 92, 95fQ 10 (temperature coefficient), enzymecatalyzedreactions and, 63QT interval, congenitally long, 432tQuaternary structure, 33–35, 35fof hemoglobins, allosteric properties and,42–46stabilizing factors and, 35R groups, amino acid properties affected by,18, 18tpK/pK a , 18R (relaxed) state, of hemoglobin,oxygenation and, 43, 43f, 44fRab protein family, 511RAC3 coactivator, 472, 472tRadiation, nucleotide excision-repair ofDNA damage caused by, 337Radiation hybrid mapping, 635tRan protein, 501, 502f, 503Rancidity, peroxidation causing, 118Rapamycin, mammalian target of (mTOR),in insulin signal transmission,466f, 467RAR. See Retinoic acid receptorRARE. See Retinoic acid response elementRate constant, 62K eq as ratio of, 62–63Rate of degradation (k deg ), control of, 74Rate-limiting reaction, metabolism egulatedby, 73Rate of synthesis (k s ), control of, 74Rb protein. See Retinoblastoma proteinReactant concentration, chemical reactionrate affected by, 62Reactive oxygen species. See Free radicals