Considering the information in this chapter on B- and Z-DNA and right- and left-handed helices, carefully analyze structures (a) and (b) below and draw conclusions about their helical nature. Which is right handed and which is left handed?

DNA and RNA are chemically very similar but are distinguished, in large part, by the presence of a 2'-OH group in RNA and a 2'-H group in DNA. Why do you suppose that both DNA and RNA have 3'-OH groups and we do not typically find nucleic acids within cells that have 3'-H groups?

DNA and RNA are chemically very similar but are distinguished, in large part, by the presence of a 2'-OH group in RNA and a 2'-H group in DNA. Why do you suppose that both DNA and RNA have 3'-OH groups and we do not typically find nucleic acids within cells that have 3'-H groups?