Protein Denaturation and Digestion

A vocabulary study set defining key terms, chemical bonds, denaturing agents, and digestive enzymes involved in protein denaturation and digestion.

Native Conformation

The biologically active shape or structural arrangement of a protein.

Denatured Protein

The inactive form of a protein that has been subjected to a denaturing agent and no longer maintains its tertiary shape.

Denaturation

Any change in protein conformation involving the loss of secondary, tertiary, or quaternary structure, caused by the disruption of intermolecular forces and bonds responsible for maintaining the native structure.

Heat and Agitation

Denaturing agents that increase the kinetic energy of parts of a protein, resulting in the disruption of hydrogen bonds holding tertiary and secondary structures together.

Salt Bridge

An ionic bond in the tertiary structure of a protein that can be disrupted by changes in pH when hydronium ions donate protons to the carboxylate anion.

Micelle

A spherical structure formed by soap or detergent molecules where polar heads face the exterior and nonpolar tails are tucked into the interior.

Disulfide Bridge

A strong covalent bond formed between cysteine amino acids containing sulfur that contributes to a protein's tertiary structure and can be cleaved by heavy metal cations.

Heavy Metal Cations

Positively charged ions from transition elements (such as silver or mercury two) or group 4 elements (such as lead) that have a high affinity for sulfur-containing groups and disrupt disulfide bonds.

Pepsin

A digestive enzyme that activates in the stomach to begin the hydrolysis of large protein molecules into oligopeptides and amino acids.

Trypsin and Chemotrypsin

Digestive enzymes located in the small intestine that catalyze the hydrolysis of polypeptides and oligopeptides into free amino acids.

Hydrolysis

The type of chemical reaction occurring during protein digestion that cleaves amide functional groups (peptide bonds) to release individual amino acids.

Amino Acids

The fundamental building blocks of proteins that are small enough to pass through the semipermeable membrane of the intestine, enter cells, undergo catabolism, and provide energy.