Q. 16.4 - An Introduction to General, Organic, and Biological Chemistry

Question

How does the polarity of the R group in leucine compare to the R group in serine?

Step-by-Step Solution

Answer

The R group in lysine is the isobutyl moiety (alkyl side chain), which is non-polar because it does not form hydrogen bonds with water.

Step 1: Given data.

To find  the polarity of the R group in leucine compare to the R group in serine? 

Step 2: Introduction.

Proteins are constructed from amino acids. There is one hydrogen atom and one amine group in each of these.$\left(-{\mathrm{NH}}_2\right)$, one carboxylic acid group$(-\mathrm{COOH})$ and one side chain (R group) joined to the central carbon atom. Proteins are composed of two amino acids that are linked together by peptide bonds. Depending on the structure, the R group can be polar, neutral, or charged.

Step 3:The R group in Serine.

The $\mathrm{R}$group in Serine is$-{\mathrm{CH}}_2-\mathrm{OH}$ It is polar because its structure contains hydroxyl groups that can form hydrogen bonds with water.

The R group in lysine is the isobutyl moiety (alkyl side chain), which is non-polar because it does not form hydrogen bonds with water.