Georgia Tech School of Biology
Fall 2011Biol 1510
Sit with people you like to work with, in groups of 3, 4, or 5. Have clickers out.
Download Wolfe-Simon et al. paper on arsenic life, and the arsenic life
worksheet
Georgia Tech School of Biology
Fall 2011Biol 1510
Arsenic life
Which of the following is NOT one of the six major elements that make up life on earth?a) Hydrogenb) Sulfurc) Phosphorusd) Calciume) Nitrogen
Georgia Tech School of Biology
Fall 2011Biol 1510
Arsenic life
What cellular macromolecules contain large amounts of phosphorus?a) Membrane lipidsb) Polysaccharidesc) Nucleic acidsd) Proteinse) All of the above
Georgia Tech School of Biology
Fall 2011Biol 1510
Arsenic life
Cells have difficulty distinguishing between arsenic and phosphorus because:a) Arsenic has a similar atomic radius to
phosphorusb) Arsenic has similar electronegativity as
phosphorusc) Arsenic lies immediately below phosphorus in
the periodic tabled) All of the abovee) None of the above
Georgia Tech School of Biology
Fall 2011Biol 1510
Periodic table of the elements
Georgia Tech School of Biology
Fall 2011Biol 1510
Sit with people you like to work with, in groups of 3, 4, or 5. Have clickers out.
Download Wolfe-Simon et al. paper on arsenic life, and the arsenic life
worksheet
Georgia Tech School of Biology
Fall 2011Biol 1510
Fig. 1 Growth and electron microscopy of strain GFAJ-1.
F Wolfe-Simon et al. Science 2011;332:1163-1166
Published by AAAS
Georgia Tech School of Biology
Fall 2011Biol 1510
Fig. 2 NanoSIMS analyses of GFAJ-1: extracted DNA and whole-cells elemental ratio maps.
F Wolfe-Simon et al. Science 2011;332:1163-1166
Published by AAAS
Georgia Tech School of Biology
Fall 2011Biol 1510
Fig. 3 X-ray analysis of GFAJ-1 +As/–P described similarity of As coordinated like P in DNA. (A) EXAFS comparisons of the Fourier transformed data for As in model environments and
GFAJ-1 (washed and fixed, collected on whole cells).
F Wolfe-Simon et al. Science 2011;332:1163-1166
Published by AAAS
Georgia Tech School of Biology
Fall 2011Biol 1510
Arsenic life
Wolfe-Simon et al. showed that in GFAJ-1 cells, most of the radio-labeled arsenic was present in:a) DNA & RNAb) Proteinsc) Lipidsd) A phenol-soluble fractione) An aqueous fraction after organic extraction
Georgia Tech School of Biology
Fall 2011Biol 1510
Arsenic life
GFAJ-1 is:a) An extraterrestrial life formb) An obligate arsenophile (needs arsenic for
growth)c) A new species or strain of the Halomonas
genus, known halophilesd) A bacterium that is able to “breathe” arsenate