Across
- 1. _____ focusing separates proteins based on their acidic and basic residues
- 6. Measure of the total activity retained after each purification step as a percentage of the activity in the crude extract.
- 8. An enhanced column chromatography technique. The separation materials are more finely divided and thus possess more interaction sites, resulting in greater resolution. Because the column material is so fine, pressure must be applied to obtain adequate flow rates.
- 12. A procedure that yields several fractions of decreasing density, each still containing hundreds of different proteins, which are assayed for the activity being purified
- 13. _____-dimensional electrophoresis is the use of isoelectric focusing and SDS-PAGE for high resolution separations
- 15. ___ exchange chromatography, where proteins are separated based on charge where a mixture of proteins is percolated through a column of beads that contain a charged group, such as a carboxylate group. Proteins bearing charges opposite those on the bead will bind. The bound proteins can be eluted by washing with a buffer containing salt
- 16. Once done with two-dimensional electrophoresis and proteins are separated, they can be identified through mass_____.
- 18. Fluid on the top layer of centrifuged tube
- 19. The mixture formed when a tissue is treated in such a way that the plasma membranes are disrupted
- 21. Gel electrophoresis technique that help separate only by mass. Negative charges on the many SDS molecules bound to the protein “swamp” the normal charge on the protein and cause all proteins to have the same charge-to-mass ratio. Thus, proteins will differ only in their mass.
Down
- 2. The fraction that has more enzyme activity than any other fraction that then serves as the source of material to which more-discriminating purification techniques are applied
- 3. Molecular exclusion chromatography, aka ____, is a technique for separating proteins on the basis of size. A mixture of proteins is percolated through a column of porous beads. Large proteins are excluded from the beads and exit the column first. Smaller proteins, because they enter the beads and take a longer path, exit subsequently
- 4. The ____ of a protein is the pH at which its net charge is zero.
- 5. A technique for separating biomolecules, such as nucleic acids and proteins, on the basis of charge and size. Helps check purification efficacy. When placed under an electric field, the biomolecules move through the gel (a cross-linked polymer such as polyacrylamide), with larger molecules moving more slowly than smaller molecules.
- 7. activity enzyme activity:total protein in enzyme assay
- 9. Proteins precipitate out of solution at high salt concentrations due to competition between the salt ions and the protein for the water of solvation to keep the protein in solution
- 10. Affinity chromatography purifies protein based on their high ____ to specific chemical groups or molecules
- 11. Proteins are purified on the basis of differences in solubility, ____, charge, and specific binding affinity
- 14. The test after each purification to see whether the purification is working based on unique properties of the protein
- 17. Heavy material at the bottom of the centrifuged tube
- 20. Process that helps dissolve proteins