Sedimentation coefficient: Difference between revisions

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


m= mass of [[Particle|particle]]


v= partial specific volume


'''Key:'''
p= [[Density|density]] of the medium


m= mass of [[particle|particle]]
f= frictional coefficient


v= partial specific volume
(1-vp) = the buoyant force of the medium


p= [[density|density]] of the medium
<br>


f= frictional coefficient
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; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>.


(1-vp) = the buoyant force of the medium
Several other aspects affect the sedimentation velocity including [[Atomic mass|mass]], a heavier molecule moves more quickly<ref>Berg, J., Tymoczko, J. &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; 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; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>.


<br>


 
=== References ===
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; 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; 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; 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; Stryer, L. (2011) 'Biochemistry'. 7 edition. New York: W. H. Freeman. pp. 78</ref>.
 
 
 
=== References ===


<references />
<references />

Revision as of 16:59, 27 November 2014

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