Quiz on Concentrating Protein Solutions

What is the most common method for purification after extraction and isolation?

• Filtration

• Concentrating Protein Solutions

• Chromatography

• Electrophoresis

Which salt is commonly used for precipitating proteins out of solution?

• Calcium carbonate

• Potassium chloride

• Sodium chloride

• Ammonium sulfate

What is the primary benefit of concentrating protein solutions?

• Decrease in purity

• Reduction in volume of extract

• Increase in volume

• Increase in temperature

What is the principle behind salting out proteins?

• Increased pH

• Increased temperature

• Decreased solubility due to reduced water availability

• Increased solubility

At what temperature should the salting out process be maintained to avoid irreversible denaturation?

• 0°C

• 25°C

• 4°C

• Room temperature

What is the purpose of using ammonium sulfate in protein precipitation?

• To enhance protein denaturation

• To decrease protein concentration

• To stabilize proteins and prevent proteolysis

• To increase protein solubility

Which method is used to remove salt after ammonium sulfate precipitation?

• Dialysis

• Centrifugation

• Lyophilization

• Filtration

What is the role of organic solvents in protein precipitation?

• Stabilize proteins

• Increase protein concentration

• Decrease solubility by reducing water activity

• Increase solubility

Which of the following is a disadvantage of using polyethylene glycol (PEG) for precipitation?

• It denatures proteins

• Difficulty in removing PEG

• It is not water-miscible

• It is expensive

What happens to proteins at their isoelectric point (pI)?

• They remain unchanged

• They become more soluble

• They denature

• They aggregate and precipitate