1, the removal of calcium ions in fermentation broth, usually with D.

A, sulfuric acid B, hydrochloric acid C, sodium hydroxide D, oxalic acid

2. Compared with salting-out method, the resolution of organic solvent precipitation method is better than salting-out method A. ..

A, high B, low C, almost D, not necessarily.

3. According to the difference of C, it can be divided into adsorption chromatography, partition chromatography, ion exchange chromatography, gel chromatography, affinity chromatography and so on.

A, mobile phase state B, operating pressure C, separation mechanism D, stationary phase morphology

4. Generally, the developing agent used in thin-layer chromatography of alumina and silica gel is mainly solvent B, and a certain proportion of polar organic solvent is added.

A, polarity b, lipophilic c, hydrophilic d, inorganic

5, alumina and silica gel thin layer chromatography in the separation of acidic or alkaline compounds, often need to add a small amount of D.

So as to prevent tailing.

A, acid b, alkali c, salt d, acid or alkali

6. For weak acid and weak base resin, the pH value of the solution has a great influence on the degree of dissociation and adsorption capacity of the resin; For weakly acidic resin, it can only be exchanged under D condition; For weakly basic resins, exchange can only be carried out under conditions.

A, alkaline neutral b, acidic alkaline

C, neutral acidity d, basic acidity

7. Generally speaking, the smaller the hydration radius of ions, the greater the affinity between ions and resin active groups.

Adsorbed by resin.

A, Freshman B, Xiao Yi C, Xiao Nan D, Da Nan

8. Crosslinking degree D, fluffy structure, swelling degree and exchange rate of resin, but exchange selectivity is poor.

A, slow size b, small big slow

C, big, small and fast, D, small and fast.

9. In the process of physical extraction, the partition coefficient of weakly acidic electrolyte decreases with the decrease of pH, b.

A, decrease B, increase C, keep D, the change is not necessarily.

10. In extraction, the existence of inorganic salts can improve the solubility of solute in water phase, which is beneficial to the distribution of solute to organic phase.

A, reduce B, increase C, maintain D, influence

1 1, after cell rupture, a large number of charged inclusions are released into the water phase, and the conductivity is b.

A, down b, up c, constant d, not necessarily.

12. In ion exchange chromatography, C determines the degree of dissociation of resin exchange groups and exchange ions, thus affecting exchange capacity and exchange selectivity.

A, temperature b, flow rate c, solution pH d, resin crosslinking degree.

13. The strength of cell wall depends not only on the crosslinking degree of network polymer structure, but also on the type of polymer and the thickness of cell wall. When using high pressure homogenization method, the cells below A are easy to be broken.

A, bacteria B, yeast C, fungi D, plant cells

14. In suspension, the more A particles, the larger the specific surface area, the more obvious the surface effect between solid and liquid, and the more separation.

A, minor difficulties B, major difficulties

C, small big easy D, easy size.

15. In ion exchange chromatography, pH value is the most important operating condition. When selecting, it should be considered to be within the target stable pH value range; Do C.

A, the target can be ionized; b, the resin can be ionized.

C, the target can be ionized; Resin can ionize d, and solvent can ionize d.