Feb 5

Question 1

What are Fridel Pairs?

Answer 1

They are hkl vectors that have same intensity if no anomalous scattering, it is when go 90 degrees from a set of planes in the crystal,

Question 2

Do phases or amplitudes matter more to get image?

Answer 2

Phases

Question 3

Can you use phases from a similar structure to get a new structure?

Answer 3

Yes, if you have structure, can find phases used to get it, then apply those phases to your new protein that is slightly different, will get new domain etc.

Question 4

What is single isomorphous replacement?

Answer 4

It is when add heavy atom to protein crystals. Collect intensities of crystal with and without heavy atom. Then remove unbound metal, and unit cell should not change to get good data

Question 5

How to locate atoms using amorphous replacement?

Answer 5

you do the DP of the PH, then minus the P, so get just H. The resulting intensitites can be fourier transformed to get the phase. This uses an estimated scattering and B factor for the atom