20.Why is the additional (ring)nitrogen in tryptophan not very basic? -C02h NH2 Cyclic amines are not bas car in The additional amine s oup is offset by an additional carboxylic acid group. E)It is sp2hybridized as therefore not as basic. Ans:C 21.What is the name of the DNA base shown? A)Guanine B)Cytosine C)Adenine D)Uracil E)Thymine Ans:A 22.In a DNA molecule,at which point would the base shown be attached to a deoxyribose fragment? A)1B)2C)3D)4E)5 Ans:E Page6 Page 6 20. Why is the additional (ring) nitrogen in tryptophan not very basic? N H2C C NH2 CO2H H H A) Cyclic amines are not basic. B) It is too far from the carboxyl group to be effected. C) Aromatic amines are weakly basic because of resonance. D) The additional amine group is offset by an additional carboxylic acid group. E) It is sp2 hybridized as therefore not as basic. Ans: C 21. What is the name of the DNA base shown? N N N N O H H H2N A) Guanine B) Cytosine C) Adenine D) Uracil E) Thymine Ans: A 22. In a DNA molecule, at which point would the base shown be attached to a deoxyribose fragment? N N N N O H H H2N 1 3 2 5 4 A) 1 B) 2 C) 3 D) 4 E) 5 Ans: E