Harpers

692 / INDEXValine (cont.)interconversion of, 240requirements for, 480Valinomycin, 99Van der Waals forces, 7Vanadium, 496tVariable numbers of tandemly repeatedunits (VNTRs), in forensicmedicine, 411Variable regions/segments, 591–592, 594fgene for, 593DNA rearrangement and, 325–326,393, 593–594immunoglobulin heavy chain, 591, 592f,594fimmunoglobulin light chain, 325–326,393, 591, 592f, 594fVascular system, nitric oxide affecting,571–573, 573f, 574tVasodilators, 556nitric oxide as, 571–573, 573f, 574tVDRE. See Vitamin D response elementVector, 414cloning, 400–402, 401f, 402t, 403f, 414expression, 402Vegetarian diet, vitamin B 12 deficiency and,491Velocityinitial, 64inhibitors affecting, 68, 68f, 69fmaximal (V max )allosteric effects on, 75–76inhibitors affecting, 68, 68f, 69fMichaelis-Menten equation indetermination of, 65–66, 66fsubstrate concentration and, 64, 64fVery low density lipoprotein receptor, 208Very low density lipoproteins, 125, 205,206t, 207hepatic secretion of, dietary and hormonalstatus and, 211–212, 213fmetabolism of, 125, 126f, 207–209, 210fin triacylglycerol transport, 207, 208f,210fVesiclescoating, 509, 510fbrefeldin A affecting, 510–511secretory, 498, 500ftargeting, 509, 510ftransport, 498, 508–511, 509t, 510fVimentins, 577t, 578Vinculin, 540, 541fViral oncogenes. See OncogenesViruses, host cell protein synthesis affectedby, 370–371, 371fVision, vitamin A in, 482t, 483, 484fVitamin A, 482–484, 482t, 483f, 484fdeficiency of, 482t, 483–484excess/toxicity of, 484functions of, 482t, 483in vision, 482t, 483Vitamin B complex. See also specific vitaminin citric acid cycle, 133coenzymes derived from, 50–51, 51fVitamin B 1 (thiamin), 482t, 488–489, 489fin citric acid cycle, 133coenzymes derived from, 51deficiency of, 482t, 489pyruvate metabolism affected by, 140,143, 489Vitamin B 2 (riboflavin), 86, 482t, 489–490in citric acid cycle, 133coenzymes derived from, 50–51, 489,490deficiency of, 482t, 490dehydrogenases dependent on, 87Vitamin B 6 (pyridoxine/pyridoxal/pyridoxamine), 482t, 491, 491fdeficiency of, 482t, 491xanthurenate excretion in, 258, 258fexcess/toxicity of, 491Vitamin B 12 (cobalamin), 482t, 491–492,492fabsorption of, 491–492intrinsic factor in, 477, 491–492deficiency of, 482t, 492functional folate deficiency and, 492,494in methylmalonic aciduria, 155Vitamin B 12 -dependent enzymes, 292f, 492Vitamin C (ascorbic acid), 163, 482t,495–496, 496fas antioxidant, 119in collagen synthesis, 38, 496, 535deficiency of, 482t, 496collagen affected in, 38–39, 496,538–539iron absorption and, 478, 496supplemental, 496Vitamin D, 482t, 484–486in calcium absorption, 477, 484,484–485deficiency of, 482t, 484, 485ergosterol as precursor for, 118, 119fexcess/toxicity of, 485–486metabolism of, 484–485, 485freceptor for, 471Vitamin D 2 (ergocalciferol), 484Vitamin D 3 (cholecalciferol)synthesis of in skin, 445, 446f, 484, 485fin vitamin D metabolism, 484, 485fVitamin D-binding protein, 445Vitamin D receptor-interacting proteins(DRIPs), 472t, 473Vitamin D response element, 459tVitamin E, 482t, 486, 486fas antioxidant, 91, 119, 486, 487fdeficiency of, 482t, 486Vitamin H. See BiotinVitamin K, 482t, 486–488, 488f, 604calcium-binding proteins and, 487–488,488fin coagulation, 486–488, 488fcoumarin anticoagulants affecting,604deficiency of, 482tVitamin K hydroquinone, 487, 488fVitamins, 2, 481–496, 482t. See also specificvitaminin citric acid cycle, 133digestion and absorption of, 477–478lipid- (fat) soluble, 482–488absorption of, 475water-soluble, 488–496VLA-1/VLA-5/VLA-6, 622tVLDL. See Very low density lipoproteinsVNTRs. See Variable numbers of tandemlyrepeated unitsVoltage-gated channels, 424, 568tvon Gierke’s disease, 152t, 300Von Willebrand factor, in plateletactivation, 605Warfarin, 486, 604phenobarbital interaction and,cytochrome P450 inductionaffecting, 628vitamin K affected by, 487Water, 2, 5–9as biologic solvent, 5, 6fbiomolecular structure and, 6–7, 6tdissociation of, 8–9in hydrogen bonds, 5, 6fas nucleophile, 7–9permeability coefficient of, 419fstructure of, 5, 6fWater solubility, of xenobiotics, metabolismand, 626Watson-Crick base pairing, 7, 303Waxes, 111Weak acids, 9buffering capacity of, 11–12, 12fdissociation constants for, 10–11, 12Henderson-Hasselbalch equationdescribing behavior of, 11, 12fphysiologic significance of, 10–11pK/pK a values of, 10–13, 12t,Weak bases, 9Wernicke-Korsakoff syndrome, 482tWernicke’s encephalopathy, 489Western blot transfer procedure, 403, 404f,414White blood cells, 620–624. See also specifictypegrowth factors regulating production of,610recombinant DNA technology in studyof, 624White thrombus, 598White (fast) twitch fibers, 574–576, 575tWhole genome shotgun approach, 634Williams syndrome, 539