Catalyzed: New pathway with lower activation energy, often multiple steps. | Uncatalyzed: Typically has a high-energy transition state, leading to a slow reaction.

Catalyzed: Lower $E_a$ due to an alternate reaction pathway. | Uncatalyzed: Higher $E_a$, requiring more energy for the reaction to proceed.

Catalyzed: Often involves multiple steps with lower energy barriers. | Uncatalyzed: May involve fewer steps, but with a higher energy barrier.

A substance that speeds up a chemical reaction without being consumed, by providing an alternate reaction pathway with a lower activation energy. It is consumed in one step and then regenerated in a later step.

The minimum energy required for a reaction to occur.

Catalysts lower the activation energy ($E_a$) of a reaction.

Catalysts do not change the enthalpy (ΔH) of a reaction.

Catalysts are written above the reaction arrow in chemical equations, not as reactants or products.

It speeds up the reaction.

More molecules have enough energy to react, thus speeding up the reaction.

It affects the rate at which equilibrium is reached, but does not change the position of the equilibrium.

It orients them more favorably for a reaction or lowers the activation energy.

It acts as a catalyst, providing an alternate pathway and lowering the activation energy, thus speeding up the reaction.