Biochemistry: Enzymes and Catalysts

Catalysts and Enzymes

• Catalysts increase chemical reaction rates by lowering activation energy.
• Enzymes are organic catalysts that facilitate biochemical reactions in living organisms.

Active Site and Substrate

• The active site is a uniquely shaped region of the enzyme that binds to the substrate.
• Substrates are the biological molecules upon which enzymes act.

Enzyme Function

• Enzymes bind to substrates at the active site, enabling a chemical reaction (catalysis) to occur.
• After the reaction, the enzyme releases the transformed substrate, now referred to as the product, and can catalyze additional reactions.

Denaturation

• Denaturation occurs when an enzyme's shape is altered, often due to changes in temperature, pH, or the presence of poisons.
• This alteration can prevent the enzyme from functioning effectively.

Factors Affecting Enzyme Activity

• Temperature changes can alter enzyme shape and function, affecting reaction rates.
• Activators enhance enzyme activity, allowing better binding to substrates.
• pH levels impact protein structure; extreme pH conditions can cause denaturation.
• Inhibitors can reduce enzyme activity: competitive inhibitors block the active site, while allosteric inhibitors modify the enzyme's shape.

Lock and Key Model

• Enzymes can be described using the lock and key analogy, where each enzyme is a specific lock and each substrate is a unique key, emphasizing their specificity in catalysis.

Specificity of Enzymes

• Enzymes typically bind to only one type of substrate, due to their specialized functions.

Activation Energy and Reaction Rates

• Enzymes lower the activation energy of reactions, leading to faster reaction rates compared to uncatalyzed processes.

Temperature Effects on Enzyme Activity

• Increasing temperature usually accelerates reactions, while extreme heat can denature enzymes, halting their activity.

pH and Enzyme Activity

• Each enzyme has an optimal pH range that supports its activity; deviations from this range can slow down functioning and impact overall reaction rates.

Explore the fascinating world of enzymes and catalysts in biochemical reactions. This quiz covers their functions, the importance of active sites, the process of denaturation, and factors that affect enzyme activity. Test your knowledge on how these biological catalysts operate and their role in living organisms.