Enzymes and Catecholase — Vocabulary

A vocabulary set of terms from the enzyme lab notes with concise definitions.

Enzyme

Protein catalyst that provides surfaces for reactants to meet in the proper orientation; not consumed by the reaction.

Catalyst

Substance that speeds up a chemical reaction without being consumed.

Substrate

Reactants that bind to an enzyme’s active site.

Product

Substances produced by an enzymatic reaction.

Active site

Region of the enzyme where substrates bind and the chemical reaction occurs; its shape/charges determine specificity.

Specificity

Enzymes are highly selective; only certain substrates fit the active site.

Catecholase (catechol oxidase)

Plant enzyme found in potato extract that oxidizes catechol to benzoquinone.

Catechol

Substrate for catecholase that is converted to benzoquinone.

Oxygen (O2)

Reactant that combines with catechol in the enzyme-catalyzed reaction.

Benzoquinone

Brown-colored product of catechol oxidation; contributes to fruit browning.

Fruit browning reaction

Enzymatic browning resulting in benzoquinone formation, visible as brown color.

Hydroquinone

Molecule similar to catechol used to test enzyme specificity.

Denaturation

Unfolding of an enzyme’s structure (often due to heat) that disrupts the active site.

Temperature effect on enzyme activity

Enzyme activity depends on temperature: higher temps increase molecular motion but can denature; low temps slow reactions.

Potato extract

Source of catecholase used in the lab experiments.

Vesicles

Membrane-bound compartments that store catecholase in undamaged cells.

Baselines/Control

Standards established in experiments to determine whether the reaction occurred and to compare conditions.