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20. In most proteins this amino acid\'s side chain is found clustered away from

ID: 475725 • Letter: 2

Question

20. In most proteins this amino acid's side chain is found clustered away from the aqueous exterior of the protein as a result of which interaction?

a) Hydrophobic effect

b) Charge-charge (ionic)

c) Dipole-dipole

d) Van der Waals (dispersion)

A protein has a pI of 6.5. If I want to use an anion exchange resin (there is a +ve charge on the resin) to bind the protein, what pH could I perform the separation at?

a) pH 8

b) pH 6.5

c) pH 5

d) The pH doesn't matter

A protein has a pI of 7, what will be the net charge on the protein at pH 5?

a) negative

b) positive

c) no net charge

d) both positive and negative

A protein has a pI of 6.5. If I want to use an anion exchange resin (there is a +ve charge on the resin) to bind the protein, what pH could I perform the separation at?

HoN CH C OH CH CH2 CH3

Explanation / Answer

20. Answer:- a

The organic groups which are water repellent are called hydrophobic groups. These try to remain away from water.

Examples of such groups include:- hydrocarbon

On the other hand the groups which are water attractive are called hydrophilic groups.

Example:- -NH2 group