C1.9 Formation of Hydrogen Bonds & its Importance

Semester 1: Foundation of Basic Science
Case 1: Chemistry of Life

Obj 9: Formation of Hydrogen Bonds & its Importance

Hydrogen Bonds

-attractive force between one electronegative atom and a hydrogen covalently bonded to another electronegative atom

-results from a dipole-dipole force with a hydrogenatom bonded to nitrogen, oxygen or fluorine (thus the name “hydrogen bond”, which must not be confused with a covalent bond to hydrogen.

How are they formed??

A hydrogen bond is formed when a charged part of a molecule having polar covalent bonds forms an electrostatic (charge, as in positive attracted to negative) interaction with a substance of opposite charge. Molecules that have non-polar covalent bond do not form hydrogen bonds.

Strength

Hydrogen bonds are classified as weak bonds because they are easily and rapidly formed and broken under normal biological conditions.

What classes of compounds can form hydrogen bonds?

Under the right environmental conditions, any compound that has polar covalent bond can form hydrogen bonds.

Importance

Hydrogen bonds are extremely important in biological systems. Thier presence explains many of the properties of water. They are used to stabilize and determine the structure of large macormolecules like proteins and nucleic acids. They are involved in the mechanism of enzyme catalysis