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patanjali.purpose
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Green Fluorescent Protein (GFP) is a protein that emits bright light in the green segment of the visible spectrum upon exposure to blue light. Its properties were first researched in 1962 by Osamu Shimomura, a Japanese scientist who studied the bioluminescence of Crystal Jellyfish, or Aequorea victoria. Shimomura discovered that such biologically-generated glow is produced when the jellyfish produces calcium ions. The ionized calcium is absorbed by a protein that produces blue luminescence upon binding with calcium, called Aequorin. Crystal jellyfish typically have nodes of Aequorin on the rim of their umbrella, but Shimomura found that these photosensitive organs are composed of another type of protein. The blue light resulting from the Aequorin calcium binding is received by the protein now known as GFP. Since GFP's major excitation peak is at a wavelength of 395nm, or in other words - blue light, it becomes active and emits visible light whose peak is at 509nm, i.e., green light. This creates a circle of greenish light around the jellyfish's umbrella. Shimomura et al received a Nobel Prize in Chemistry for the discovery and development of GFP.
GFP has numerous uses in cellular and molecular biology, most commonly as a reporter of expression. In layman's terms, Green Fluorescent Protein is used as an indicator to the activation of certain genes into which it is spliced. This mean that only the cells in which those specific genes are activated will fluoresce green under a blue light. This has been tremendously useful in mapping out the connection between DNA strings in genes and the biological systems which they control.
Another field where GFP was found to be profoundly useful is fluorescence microscopy. Before the discovery of GFP and its derivatives, fluorescent microscopists used synthetic fluorophores to dye the target sample. However, such fluorophores were found to be highly phototoxic, as the light they emitted was transferred to oxygen molecules in the cells under examination. This provoked the creation of oxygen radicals that could kill a living cell in seconds. GFP has proven to be dramatically less phototoxic, thereby revolutionizing this field of science.
1) The contribution of the discovery of GFP to fluorescence microscopy is regarded by the author with:
a) subtle dismissal
b) scientific zeal
c) explicit appreciation
d) blunt disregard
e) reluctant acknowledgement
Pls explain your pick.
GFP has numerous uses in cellular and molecular biology, most commonly as a reporter of expression. In layman's terms, Green Fluorescent Protein is used as an indicator to the activation of certain genes into which it is spliced. This mean that only the cells in which those specific genes are activated will fluoresce green under a blue light. This has been tremendously useful in mapping out the connection between DNA strings in genes and the biological systems which they control.
Another field where GFP was found to be profoundly useful is fluorescence microscopy. Before the discovery of GFP and its derivatives, fluorescent microscopists used synthetic fluorophores to dye the target sample. However, such fluorophores were found to be highly phototoxic, as the light they emitted was transferred to oxygen molecules in the cells under examination. This provoked the creation of oxygen radicals that could kill a living cell in seconds. GFP has proven to be dramatically less phototoxic, thereby revolutionizing this field of science.
1) The contribution of the discovery of GFP to fluorescence microscopy is regarded by the author with:
a) subtle dismissal
b) scientific zeal
c) explicit appreciation
d) blunt disregard
e) reluctant acknowledgement
Pls explain your pick.
