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Protonation

The addition of a proton (H+) to a molecule, often affecting its charge.

Deprotonated

The state of a molecule that has lost a proton, often resulting in a negative charge.

Zwitterion

A molecule with both positive and negative charges, but with an overall neutral charge.

pH Scale

A measure of the acidity or basicity of a solution, ranging from 0 (acidic) to 14 (basic). A pH of 7 is neutral.

Denaturation

The process where proteins lose their three-dimensional structure and therefore their function due to external stressors.

Hydrophobic

A term describing molecules that do not interact well with water.

Hydrophilic

A term describing molecules that interact well with water.

Cofactor

A non-protein chemical compound that is required for the biological activity of a protein, often a metal ion or a coenzyme.

Lyase

Enzymes that catalyze the addition or removal of groups from double-bonded substrates.

Oxidoreductase

Enzymes that catalyze oxidation-reduction reactions, transferring electrons from one molecule to another.

Transferase

Enzymes that transfer a functional group from one molecule to another.

Hydrolase

Enzymes that catalyze the cleavage of bonds by the addition of water.

Amino acid

The basic building blocks of proteins, characterized by an amino group, a carboxyl group, and a side chain (R group).

Essential amino acids

Amino acids that cannot be synthesized by the human body and must be obtained from the diet.

Primary structure

The linear sequence of amino acids in a protein.

Secondary structure

The local folded structures that form within a protein due to hydrogen bonding (e.g., alpha helices, beta sheets).

Tertiary structure

The overall three-dimensional shape of a protein, determined by interactions among various side chains.

Albumin

A major plasma protein involved in transporting various substances and maintaining osmotic pressure.

Gamma globulins

A class of plasma proteins that includes antibodies.

Denatured protein

A protein that has lost its native structure and function due to external stressors.

Disulfide bond

A covalent bond between the sulfur atoms of two cysteine residues in a protein, stabilizing its structure.