Biochemistry: Bonding and Basic Concepts (Video)

Ten vocabulary flashcards covering bonding types, pH, acids/bases, and dehydration synthesis as discussed in the lecture video.

Ionic bond

Electrostatic attraction between oppositely charged ions (e.g., Na+ and Cl−) formed by transfer of electrons between atoms with a large electronegativity difference.

Covalent bond

Bond formed by sharing electrons between atoms; can be nonpolar (equal sharing) or polar (unequal sharing) depending on electronegativity differences.

Polar covalent bond

A covalent bond with unequal electron sharing that creates partial charges on atoms (dipole), as in the O–H bonds of water.

Nonpolar covalent bond

A covalent bond with approximately equal sharing of electrons, resulting in no partial charges (e.g., H–H, C–C; some C–H bonds are near nonpolar).

Hydrogen bond

A weak intermolecular attraction where a hydrogen atom bonded to a highly electronegative atom (O or N) interacts with another electronegative atom; crucial in water and biology.

Dissociation

Separation of a compound into ions in solution (e.g., NaCl → Na+ + Cl−); not all dissolutions involve dissociation (e.g., glucose dissolves as molecules).

pH

The negative logarithm of the hydrogen-ion concentration; pH = −log[H+]. Lower pH = more acidic; higher pH = more basic.

Acid

A substance that donates hydrogen ions to a solution, increasing [H+]; e.g., hydrochloric acid (HCl).

Base

A substance that accepts hydrogen ions (or donates OH−); e.g., ammonia (NH3) forms NH4+. In biology, bases help raise pH.

Dehydration synthesis

A condensation reaction that forms a larger molecule by removing water, joining two smaller molecules (e.g., forming sucrose from glucose and fructose).