Final answer:
Glutamic acid is the only polar amino acid from the list provided, characterized by its hydrophilic properties due to its carboxylic acid group in the side chain.
Step-by-step explanation:
The amino acids listed in the question have different properties based on their side chains. Of the amino acids provided - glutamic acid, valine, glycine, tryptophan, and proline - only glutamic acid is a polar amino acid. The side chain of glutamic acid contains a carboxylic acid group, making it hydrophilic and therefore polar. This allows it to interact with water and other polar molecules, which is a key feature of polar amino acids. Valine and proline are nonpolar, glycine is neutral, and tryptophan, despite having an aromatic side chain, is typically categorized as nonpolar due to its overall hydrophobic characteristics.