Continuing with the new, newsier format introduced last week, we note the considerable media buzz concerning the NASA research by Felisa Wolfe-Simon et al. that was just published (online) by Science: A bacterium that can grow by using arsenic instead of phosphorus. The central claim of this paper is that, when growing in a high-arsenic, phosphate-free environment, a bacterial strain known as GFAJ-1 can substitute arsenate (AsO43-) for phosphate (PO43-). This claim has been hotly disputed by prominent scientists, but if it were true, the standard textbook explanations and diagrams of nucleic acids having a "sugar-phosphate backbone" would not necessarily apply to all life.
At this point, casual biology students and scientifically curious adults may be thinking, "Right.... Now what does that sugar-phosphate backbone look like, again?" Most DNA songs focus on the hydrogen bonding between complementary bases, but here's one (performed by two high school teachers) that shows you the backbone as well. Bonus points for using the word "phosphodiester"!