Transcript B1510_module3_1_arseniclife

Georgia Tech School of Biology
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
Biol 1510
Fall 2011
Georgia Tech School of Biology
Arsenic life
Which of the following is NOT one of the six
major elements that make up life on earth?
a)
b)
c)
d)
e)
Biol 1510
Hydrogen
Sulfur
Phosphorus
Calcium
Nitrogen
Fall 2011
Georgia Tech School of Biology
Arsenic life
What cellular macromolecules contain large
amounts of phosphorus?
a)
b)
c)
d)
e)
Biol 1510
Membrane lipids
Polysaccharides
Nucleic acids
Proteins
All of the above
Fall 2011
Georgia Tech School of Biology
Arsenic life
Cells have difficulty distinguishing between
arsenic and phosphorus because:
a) Arsenic has a similar atomic radius to
phosphorus
b) Arsenic has similar electronegativity as
phosphorus
c) Arsenic lies immediately below phosphorus in
the periodic table
d) All of the above
e) None of the above
Biol 1510
Fall 2011
Georgia Tech School of Biology
Periodic table of the elements
Biol 1510
Fall 2011
Georgia Tech School of Biology
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
Biol 1510
Fall 2011
Georgia Tech School of Biology
Fig. 1 Growth and electron microscopy of strain GFAJ-1.
F Wolfe-Simon et al. Science 2011;332:1163-1166
Biol 1510
Published by AAAS
Fall 2011
Georgia Tech School of Biology
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
Biol 1510
Published by AAAS
Fall 2011
Georgia Tech School of Biology
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
Biol 1510
Published by AAAS
Fall 2011
Georgia Tech School of Biology
Arsenic life
Wolfe-Simon et al. showed that in GFAJ-1
cells, most of the radio-labeled arsenic was
present in:
a)
b)
c)
d)
e)
Biol 1510
DNA & RNA
Proteins
Lipids
A phenol-soluble fraction
An aqueous fraction after organic extraction
Fall 2011
Georgia Tech School of Biology
Arsenic life
GFAJ-1 is:
a) An extraterrestrial life form
b) An obligate arsenophile (needs arsenic for
growth)
c) A new species or strain of the Halomonas
genus, known halophiles
d) A bacterium that is able to “breathe” arsenate
Biol 1510
Fall 2011