28. Which of the following methods concerning absorption are INCORRECT? (A) UV-Visible spectroscopy of organic compounds is usually associated with n → π*and π → π*(B) The intensity of absorbance is proportional to the log of the absorbing species concentration (C) An atomic absorption spectrum consists of a series of line peaks (D) X-ray absorption spectroscopy (XAS) can probe the chemical surroundings around an atom of interest.

3. Consider an experiment in which nucleic acids are separated using agarose gel electrophoresis. In the gel you load the following samples: Lane 1: a population of linearized 3000-bp double-stranded DNA (dsDNA) molecules. Lane 2: a population of circular 3000-bp double-stranded DNA (dsDNA) molecules Which population of nucleic acids would most likely migrate through the gel fastest, and in which direction through the gel will these molecules migrate? (A) The linearized dsDNA would most likely migrate faster than the circular dsDNA. AlI DNA molecules would migrate toward the positive end of the gel. (B) The linearized dsDNA would most likely migrate faster than the circular dsDNA. AIl DNA molecules would migrate towards the negative end of the gel. (C) The circular dsDNA would most likely migrate faster than the linearized dsDNA. All DNA molecules would migrate toward the positive end of the gel. (D) The circular dsDNA would most likely migrate faster than the linearized dsDNA. All DNA molecules would migrate toward the negative end of the gel

其他試題