Phosphate groups are polar and allow the cell to exist in water.
Answer:
Two types of orientation behavior are as follows:
Taxis behavior:
This is a type of orientation behavior that mainly occur in response towards the external stimulus. Taxis may be positive (movement towards the stimulus) or negative ( movement away from the stimulus). Different types of taxis behavior are phototaxis, aerotaxis, chemotaxis and magnetotaxis.
Kinesis:
Kinesis may be defined as a type of orientation behavior that can change the complete movement or orientation of the organism. Kinesis is a random movement and organism can move in either direction. Different type of kinesis are klinokinesis and orthokinesis.
Answer:
The main difficulties of X-ray crystallography include:
1. It is very difficult to obtain crystals with high diffraction quality and proper size.
2. Phase analysis. In theory, X-ray crystallography technology has no requirement for the molecular weight of protein, and can obtain any high-resolution structure at the atomic level of protein. Because some proteins are very difficult to crystallize, or the quality of crystallization is very poor, there is no diffraction or only very low resolution diffraction data, which limits the X-ray crystallography analysis of protein structure.
Explanation:
http://www.creative-biostructure.com/protein-crystallization_26.htm
Homogenous mixture, or a solution.
