I\'m having a bit of difficulty understanding a research article titled \"A Bact

Question

I'm having a bit of difficulty understanding a research article titled "A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus " by Felisa Wolfe-Simon, et al. http://science.sciencemag.org/content/332/6034/1163

For this figure:

What is the Question/Hypothesis, Techniques Used, Controls, and Author’s Conclusions:

-As/+P Ratios 1.00 0.75 0.50 0.25 0.00 8.00 6.00 4.00 2.00 0.00 +As/-P 2 As/+P 23 1 Hm 31p:1C SE 7SAs:C 13.4(+2.5) 6.9(+1.6) 1 um F 2 m Fig. 2. NanoSIMS analyses of GFAJ-1: extracted DNA and whole-cells elemental ratio maps. (A) Agarose gel loaded with DNA/RNA extracted from GFAJ-1 grown (lane 2) +As-P and (lane 3)-As/+P as compared with (lane 1) a DNA standard. Genomic bands were excised as indicated and analyzed with NanoSIMS. lon ratios of 75As-12C of excised gel bands are indicated below with 2 error shown (all values multiplied by 10-). (B to G) NanoSIMS images of whole GFAJ-1 cells grown either [(B), (D), and (F) +As-P or [(O, (E), and (G)]-As/+P. Shown are the ion ratios of [(B) and (O]7As2C(D) and (E)] 31P:2C,and [(F) and (G)] secondary electron (SE). Ratios in (B) and (CO are multiplied by 10 and in (D) and (E) are multiplied by 10-3.The color bars indicate measured elemental ratios on a log scale as indicated. Length scale is as indicated on images; images contain equivalent pixel density (11)

Explanation / Answer

Question- Through this paper researcher want to tell that there is a bacteria which can grow using arsenic instead of phophrous as mostly organism have phosphrous as one of the main costituent of life macromolecules so researcher try to find alternative of phosphrous.

Technique used- They use number of techniques to identify arsenic in bacteria trace element first they grow bacteria in arseic rich media and alow to fermented for few days later they use scanning electroscopy, tranmission electroscopy, x-ray diffraction,synchrotron x-ray studies,Micro–x-ray absorption near-edge spectroscopy. This all were done to trace the radio labeled element in the bacterial geneome.

Controls- While growing bacterial colony they used two different media one with arsenic rich and other wich is control as phosprous rich later they radiolabel them to visualize there presence.

Conlusion- Author find that arsenic can replace as alternative source of phosprous in given bacterial species.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.