1. You have a mixture of three proteins X, Y, and Z.

       X is positively charged,has a mass of 100 kDa, it binds sugars.

       Y is positively charged,has a mass of 200 kDa, it does not bind sugars.

       Z is negatively charged,has a mass of 100 kDa, it does not bind sugars.

What will be the most efficient method to purify protein X fromthe mixture of X, Y, and Z?

A. washing

B. drying

C. ion-exchange chromatography

D. gel filtration chromatography

E. affinity chromatography

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2. What is the function of molecular chaperones?

A. They increase the rate of correct protein folding and preventthe formation of incorrectly folded intermediates

B. They transport ions across biological membranes

C. They catalyze chemical reactions in cells

D. They denature other proteins

E. They heat shock other proteins

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3. Arrangement of two or more polypeptide chains into amulti-subunit protein is referred to as:

A. Quaternary structure

B. Conformation

C. Tertiary structure

D. Primary structure

E. Secondary structure

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4. Research scientists are trying to clone a gene. In order toaccomplish this task they join two pieces of DNA. Which class ofthe enzymes below might accomplish this task?

A. ligases

B. lyases

C. hydrolases

D. oxidoreductases

E. isomerases