Final answer:
Glutamic acid can form ionic bonds at pH 7 due to its negatively charged side chain, while glutamine cannot as it lacks a charged side chain at this pH.
Step-by-step explanation:
At pH 7, glutamic acid can participate in ionic bonds that are not possible for glutamine. Glutamic acid has a side chain of CH2CH2COOH, which can lose a hydrogen ion to become negatively charged. This negative charge allows it to form electrostatic attractions with positively charged side chains of other amino acids, such as those with amino groups.
Glutamine, on the other hand, has an amide side chain that does not dissociate to carry a charge at physiological pH, thus it cannot participate in ionic bonding. Ionic bonds are significant in the folding and stability of proteins, contributing to the formation of a specific three-dimensional shape essential for protein function.
The types of interactions that glutamic acid can participate in at pH 7 but glutamine cannot are ionic bonding and hydrogen bonding.
Ionic bonding occurs between positively and negatively charged side chains of amino acids. For example, the attraction between an aspartic acid carboxylate ion and a lysine ammonium ion forms an ionic bond.
Hydrogen bonding, on the other hand, forms between a highly electronegative oxygen or nitrogen atom and a hydrogen atom attached to another oxygen or nitrogen atom. This type of bonding is found in polar amino acid side chains.