For 10 points, name these exceptionally strong dipole-dipole interactions.
"Low barrier" types of these entities occur in the catalytic triad of serine proteases. A unique form of these is present in borane-ammonia complexes. In RNA and proteins, they are chiefly responsible for secondary structure. Water expands upon freezing because these entities become ordered. They usually involve fluorine, nitrogen, or oxygen and their namesake element. For 10 points, name these exceptionally strong dipole-dipole interactions.
"Low barrier" types of these entities occur in the catalytic triad of serine proteases.
{hydrogen} bonds