04. OCR - 2.1.4 Enzymes - Chapter 4 - A Biology - Year 1

Keywords for OCR A Biology - Year 1 - 2.1.4 Enzymes - Chapter 4

Activation energy

The energy required to initiate a reaction.

Active site

Area of an enzyme with a shape complementary to a specific substrate, allowing the enzyme to bind a substrate with specificity.

Catalase

An enzyme that catalyses the breakdown of hydrogen peroxide.

Cofactors

Non-protein components necessary for the effective functioning of an enzyme.

Competitive inhibitor

An inhibitor that competes with substrate to bind to active site on an enzyme.

Denatured (denaturation)

Change in tertiary structure of a protein or enzyme, resulting in loss of normal function.

End-product inhibition

The product of a reaction inhibits the enzyme required for the reaction.

Endothermic

Reactions that absorb energy.

Enzyme−product complex

Complex formed as a result of an enzyme-catalysed reaction, when a substrate is converted to a product or products while bound to the active site of an enzyme.

Enzymes

Biological catalysts that interact with substrate molecules to facilitate chemical reactions. Usually globular proteins.

Exothermic

Reactions that release energy.

Induced-fit hypothesis

Modified lock and key explanation for enzyme action; the active site of the enzyme is modified in shape by binding to the substrate.

Inhibitor

A factor that prevents or reduces the rate of an enzyme-catalysed reaction.

Ion

An atom or molecule with an overall electric charge because the total number of electrons is not equal to the total number of protons. See anion and cation.

Non-competitive inhibitor

An inhibitor that binds to an enzyme at an allosteric site.

Prosthetic group

Non-protein component of a conjugated protein.

Proteases

Enzymes that catalyse the breakdown of proteins and peptides into amino acids.

Substrate

A substance used, or acted on, by another process or substance. For example a reactant in an enzyme-catalysed reaction.

Temperature coefficient (Q10)

A measure of how much the rate of a reaction increases with a 10