Which of these compounds might be ester? A: CH3CH2COCH2CH3 B: CH3COOC2H5 C: CH3CH2OCH2CH2CH2CH3 D: CH2(NH2)COOH
Which of these compounds might be ester? A: CH3CH2COCH2CH3 B: CH3COOC2H5 C: CH3CH2OCH2CH2CH2CH3 D: CH2(NH2)COOH
蛋白质分子结构中的特殊化学键包括（ ）。 A: peptide bond B: -S-S- C: Ester bond D: 离子键 E: 氢键 F: 范德华力
蛋白质分子结构中的特殊化学键包括（ ）。 A: peptide bond B: -S-S- C: Ester bond D: 离子键 E: 氢键 F: 范德华力
肌酸补剂有哪些种类？ A: 一水肌酸（creatine momohydrate） B: 二代肌酸/肌酸乙酯（creatine ethyl ester） C: 磷酸肌酸（creatine phosphate） D: 柠檬肌酸（creatine citrate）
肌酸补剂有哪些种类？ A: 一水肌酸（creatine momohydrate） B: 二代肌酸/肌酸乙酯（creatine ethyl ester） C: 磷酸肌酸（creatine phosphate） D: 柠檬肌酸（creatine citrate）
Why do aldehydes undergo nucleophilic addition reactions while esters undergo nucleophilic acyl substitution reactions? A: The carbonyl carbon of an ester is more electrophilic than that of an aldehyde. B: Aldehydes are more sterically hindered than esters. C: Once the nucleophile adds to an aldehyde, the tetrahedral intermediate is too sterically hindered to eliminate one of the attached groups. D: Once the nucleophile adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic.
Why do aldehydes undergo nucleophilic addition reactions while esters undergo nucleophilic acyl substitution reactions? A: The carbonyl carbon of an ester is more electrophilic than that of an aldehyde. B: Aldehydes are more sterically hindered than esters. C: Once the nucleophile adds to an aldehyde, the tetrahedral intermediate is too sterically hindered to eliminate one of the attached groups. D: Once the nucleophile adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic.