1. In the space below, draw a reaction showing the formation of a phosphodiester bond joining two nucleotides (one containing thymine and one containing guanine) in DNA. Do not paste in a copy of a figure. Be sure to start with the 5' end on the left side & to show which nucleotide loses -OH and which loses -H groups to form a molecule of water. Remember to draw the bases associated with the nucleotides and also label them as either a pyrimidine or purine.

2. One of the earliest drugs used to treat patients with HIV infections was the nucleotide analog AZT. A nucleotide analog has a structure and function similar to a nucleotide. Some of the nucleotide analogs being used to treat HIV infections are called dideoxy-nucleotides. Dideoxy nucleotides include a ribose sugar that lacks both a 2' and 3' hydroxyl group. Based on what you know about nucleic acid synthesis, what effect do you think these analogs have on nucleic acid synthesis?