Enzyme Notes

Enzymes

• Definition: Enzymes are modified proteins that catalyze biochemical reactions in living organisms. They are highly selective and reusable, accelerating reaction rates by $10^6$ to $10^{14}$ by lowering the activation energy $(E_a)$.

Activation Energy ($E_a$)

• Definition: The initial energy required to start a reaction. Enzymes reduce this energy.

Active Site and Anatomy

• Definition: The active site is where the enzyme binds to a substrate.

Denaturation

• Definition: Denaturation is the loss-of-function due to changes in the enzyme's 3D shape, often caused by extreme pH or high temperatures. Low temperatures reduce enzyme activity.

Factors Affecting Enzyme Activity

• Time- ↑ Time = ↑ Productivity

• Enzyme Concentration- ↑ Enzyme concentration = ↑ Productivity

• pH- Enzymes denature in very low or high pH environments.

• Temperature- Enzymes denature in high temperatures and have less activity in low temperatures. Optimal temperatures and pH levels depend on the enzyme and its environment.

Enzyme Formulas

• Substrates → Products (Enzymes are written above the arrow).

Enzyme Classification

• Enzymes are named after the reaction they catalyze, typically ending with '-ase' (e.g., Catalase, Catecholase). Some proteolytic enzymes use the suffix “-in” (e.g. Rennin).

Today’s Enzymes and Their Reactions

• Catechol + $1/2 O<em>2$ → Benzoquinone + $H</em>2O$ (Enzyme: Catecholase)

• Rennin works best at 37°C.

• $2 H<em>2O</em>2$ → $2 H<em>2O$ + $$O