Flashcard: Enzyme Kinetics and Catalysis Fundamentals — 20 carte

Enzymes catalyze reactions?

They accelerate reaction rates in biological systems.

Enzyme specificity — role?

Ensures catalysis of specific substrates or reactions.

Isozymes — definition?

Variants of enzymes with different properties for same reaction.

Rapid equilibrium hypothesis — meaning?

Assumes quick formation/dissociation of enzyme-substrate complex.

Reaction velocity equations — basis?

Derived from Michaelis-Menten assumptions and rate constants.

Temperature effects — enzyme activity?

Increases to an optimum, then declines due to denaturation.

pH influence — enzyme activity?

Maximized at optimal pH; declines outside this range.

Michaelis-Menten model — assumption?

Steady-state of enzyme-substrate complex during initial rate.

Lineweaver-Burk plot — purpose?

Linearizes Michaelis-Menten for parameter determination.

Activation energy — role?

Energy barrier that must be overcome for reaction.

Collision theory — explanation?

Reactions occur when molecules collide with proper energy and orientation.

Enzyme denaturation — cause?

High temperature, pH extremes, or chemicals disrupt structure.

Optimal temperature — definition?

Temperature at which enzyme activity is highest.

pH effect — enzyme stability?

Depends on ionization of amino acids; too high or low causes denaturation.

Vmax — meaning?

Maximum reaction velocity at enzyme saturation.

Km — significance?

Substrate concentration at half Vmax, indicates affinity.

Lineweaver-Burk — slope?

Km/Vmax, used to calculate kinetic parameters.

Enzyme specificity — models?

Lock-and-key and induced fit models.

Activation energy — lowered by?

Enzymes stabilize transition state, reducing Ea.

Collision theory — temperature effect?

Higher temperature increases collision frequency and energy.