Cys的pK<sub>1</sub>(α-COOH)为1.96,pK<sub>2</sub>(α-NH<sub>3</sub><sup>+</sup>)为8.18,pK<sub>3</sub>(R基团)为10.28,在pH为6.12的缓冲液中,该氨基酸所带电荷为()
A、正电荷
B、负电荷
C、无电荷
D、等电荷
A、正电荷
B、负电荷
C、无电荷
D、等电荷
A、NaH<sub>2sub>PO<sub>4sub>--Na<sub>2sub>HPO<sub>4sub>(pK<sub>α1sub>θ=2.12,pK<sub>α2sub>θ=7.20) B、HCOOH--HCOONa(pK<sub>αsub>θ=3.74) C、HAC--NaAC(pK<sub>αsub>θ=4.74) D、NaHCO<sub>3sub>--Na<sub>2sub>CO<sub>3sub>(pK<sub>α1sub>θ=6.38,pK<sub>α2sub>θ=10.25)
A、m<sub>t1sub>=m<sub>a2sub>,α<sub>t1sub>=α<sub>a2sub>,γ=β B、m<sub>a1sub>=m<sub>t2sub>,α<sub>a1sub>=α<sub>t2sub>,γ=β C、m<sub>t1sub>=m<sub>a2sub>,α<sub>t1sub>=α<sub>a2sub>,γ=-β D、m<sub>a1sub>=m<sub>a2sub>,α<sub>a1sub>=α<sub>t2sub>,γ=-β
A、NH<sub>2sub>OH(羟氨)(pK<sub>bsub>=8.04) B、NH<sub>3sub>·H<sub>2sub>O(pK<sub>bsub>=4.74) C、CH<sub>3sub>COOH(pK<sub>asub>=4.74) D、HCOOH(pK<sub>asub>=3.74)
A、α<sub>2sub>=α<sub>1sub> B、α<sub>2sub>=2α<sub>1sub> C、α<sub>2sub>=20.8α<sub>1sub> D、α<sub>2sub>=20.4α<sub>1sub>
A、激动中枢的I<sub>1sub>-咪挫琳受体 B、激动中枢的α<sub>1sub>受体 C、阻断中枢的α<sub>2sub>受体 D、阻断中枢的α<sub>1sub>受体 E、激动中枢M 受体
A、酚酞(pK<sub>asub>=9.1) B、中性红(pK<sub>asub>=7.4) C、甲基橙(pK<sub>asub>=3.4) D、溴酚蓝(pK<sub>asub>=4.1)
A、α<sub>1sub>=α<sub>2sub> B、α<sub>2sub>>α<sub>2sub> C、α<sub>1sub><α<sub>2sub> D、与α<sub>1sub>和α<sub>2sub>无关
A、HCl滴定NaCN(HCN:pK<sub>asub>=9.21) B、HCl滴定苯酚钠(苯酚:pK<sub>asub>=10.00) C、NaOH滴定吡啶盐(吡啶:pK<sub>bsub>=8.77) D、NaOH滴定甲胺盐(甲胺:pK<sub>bsub>=3.37)