Sedimentation coefficient: Difference between revisions

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The sedimentation coeffiecient, s, is a way of mathmatically quantfying how a [[Molecule|molecule]] moves when subjected to a [[Centrifugal force|centrifugal force]]&nbsp;usually within a liquid medium<ref>Berg, J., Tymoczko, J. &amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>. It is calculated by using the following equation:  
The sedimentation coefficient, s, is a way of mathmatically quantfying how a [[Molecule|molecule]] moves when subjected to a [[Centrifugal force|centrifugal force]]&nbsp;usually within a liquid medium<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>. It is calculated by using the following equation:  


=== '''s = m(1-vp)/f<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>'''<br> ===
=== '''s = m(1-vp)/f<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>'''<br> ===


'''Key:'''  
'''Key:'''  
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f= frictional coefficient  
f= frictional coefficient  


(1-vp) = the buoyant force of the medium  
(1-vp) = the buoyant force of the medium<br>
 
<br>  


It is usually expressed in Svedberg units (S). The larger the S value, the quicker the molecule moves. However, it is not directly proportional to the [[Molecular weight|molecular weight]] of the [[Molecule|molecule]] as is apparent in the equation above<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>.  
It is usually expressed in Svedberg units (S). The larger the S value, the quicker the molecule moves. However, it is not directly proportional to the [[Molecular weight|molecular weight]] of the [[Molecule|molecule]] as is apparent in the equation above<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>.  


Several other aspects affect the sedimentation velocity including [[Atomic mass|mass]], a heavier molecule moves more quickly<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>. Also, if the [[Molecule|molecule]] has a shape that produces less drag, its frictional coefficient will be smaller and hence, will sediment more quickly<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>. And lastly, the [[Density|density]] of both the [[Molecule|molecule]] and the [[Solution|solution]] affects the sedimentation velocity<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>.  
Several other aspects affect the sedimentation velocity including [[Atomic mass|mass]], a heavier molecule moves more quickly<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>. Also, if the [[Molecule|molecule]] has a shape that produces less drag, its frictional coefficient will be smaller and hence, will sediment more quickly<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>. And lastly, the [[Density|density]] of both the [[Molecule|molecule]] and the [[Solution|solution]] affects the sedimentation velocity<ref>Berg, J., Tymoczko, J. &amp;amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>.<br>
 
<br>  


=== References  ===
=== References  ===


<references />
<references />

Latest revision as of 13:41, 24 October 2017

The sedimentation coefficient, s, is a way of mathmatically quantfying how a molecule moves when subjected to a centrifugal force usually within a liquid medium[1]. It is calculated by using the following equation:

s = m(1-vp)/f[2]

Key:

m= mass of particle

v= partial specific volume

p= density of the medium

f= frictional coefficient

(1-vp) = the buoyant force of the medium

It is usually expressed in Svedberg units (S). The larger the S value, the quicker the molecule moves. However, it is not directly proportional to the molecular weight of the molecule as is apparent in the equation above[3].

Several other aspects affect the sedimentation velocity including mass, a heavier molecule moves more quickly[4]. Also, if the molecule has a shape that produces less drag, its frictional coefficient will be smaller and hence, will sediment more quickly[5]. And lastly, the density of both the molecule and the solution affects the sedimentation velocity[6].

References

  1. ↑ Berg, J., Tymoczko, J. &amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78
  2. ↑ Berg, J., Tymoczko, J. &amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78
  3. ↑ Berg, J., Tymoczko, J. &amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78
  4. ↑ Berg, J., Tymoczko, J. &amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78
  5. ↑ Berg, J., Tymoczko, J. &amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78
  6. ↑ Berg, J., Tymoczko, J. &amp;amp; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78
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