Resolution: Difference between revisions
From Proteopedia
Jump to navigationJump to search
Eric Martz (talk | contribs) |
Eric Martz (talk | contribs) |
||
| Line 53: | Line 53: | ||
Once refinement of the electron density map is completed, the amount of electron density at the position of each atom determines that atom's [[Temperature|B factor or temperature value]]. | Once refinement of the electron density map is completed, the amount of electron density at the position of each atom determines that atom's [[Temperature|B factor or temperature value]]. | ||
==Determination of Resolution== | |||
The portion of the macromolecule that is best ordered in the crystal is responsible for diffraction spots that are farthest from the axis of the X-ray beam. Resolution is determined from these farthest spots based on their angle θ from the X-ray beam, using [http://en.wikipedia.org/wiki/Bragg's_law the Bragg equation] solved for ''d'': | |||
<center> | |||
''d'' = λ / (2 sin θ) | |||
</center> | |||
where λ is the X-ray wavelength, and ''d'' is the smallest distance between crystal lattice planes that scatter discrete spots. The resolution is given by ''d''. | |||
If some portions of the macromolecule are less ordered in the crystal than others, these will have a poorer resolution. The "resolution of the crystal" represents the most ordered portions. | |||
==See Also== | ==See Also== | ||
