Enzymes functions

Enzyme

A protein that acts as a catalyst to speed up biochemical reactions.

Catalyst

A substance that increases the rate of a chemical reaction without being consumed in the process.

Activation Energy (AGt)

The extra energy required to reach the transition state in a reaction.

Transition State

A high-energy state during a reaction that must be attained for the conversion of reactants to products.

Gibbs Free Energy (AG)

The difference in energy between reactants and products; negative AG indicates a spontaneous reaction.

Enzyme-Substrate Complex

A temporary complex formed when an enzyme binds to its substrate.

Michaelis-Menten Kinetics

A model describing the rate of enzymatic reactions with respect to substrate concentration.

Vmax

The maximum velocity of an enzymatic reaction when the enzyme is saturated with substrate.

Km

The substrate concentration at which the reaction velocity is half of Vmax; reflects enzyme affinity.

Non-Competitive Inhibition

A form of enzyme inhibition where the inhibitor reduces the activity without blocking the active site.

Competitive Inhibition

A form of enzyme inhibition where the inhibitor competes with the substrate for binding to the active site.

Lineweaver-Burke Plot

A graphical representation of the Michaelis-Menten equation used to determine kinetic parameters Vmax and Km.

Stabilize Transition State

The process by which enzymes lower the activation energy, facilitating the transition from substrate to product.

Induction

An increase in enzyme expression that results in an increased Vmax.

Repression

A decrease in enzyme expression that results in a decreased Vmax.

Affinity

The degree to which an enzyme is attracted to its substrate; reflected in Km values.

Phosphorylation

A biochemical process that involves the addition of a phosphate group to a molecule, often altering enzyme activity.

Desensitization

A decrease in a receptor's or enzyme's affinity for a ligand, often caused by a conformational change.

Sensitization

An increase in a receptor's or enzyme's affinity for a ligand, usually due to structural changes.