An Amino Acid Is Made to Replace Another Amino Acid $\alpha$

question 53

Multiple Choice

An amino acid is made to replace another amino acid in membrane-spanning $\alpha$ -helices by site-directed mutagenesis of the gene coding for the protein. This is done in order to determine how close together two such $\alpha$ -helices are in the structure of an integral protein. The amino acid is added to facilitate the attachment of a nitroxide group which can be used to detect position The amino acid substituted is:____________________.

• A)phenylalanine
• B)alanine
• C)cysteine
• D)methionine
• E)proline

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Definitions:

Standard Deviation

A gauge for the degree of spread or discrepancy in a series of data points.

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