Biology: Importance of Enzymes

Importance of Enzymes

• Enzymes are complex organic compounds crucial for speeding up chemical reactions in the body without changing themselves.
• Specificity is a key feature; each enzyme catalyzes one specific chemical reaction, enhancing reaction rates significantly.

Structure and Function

• Enzymes consist of active sites, where substrates bind, forming an enzyme-substrate complex.
• The reaction proceeds, transforming substrates into products, which are then released while the enzyme remains unchanged.

Models of Enzyme Action

• Lock and Key Model: Proposed by Emil Fischer, suggesting a rigid fit between substrate and enzyme, like a key in a lock.
• Induced Fit Model: Proposed by Daniel E. Koshland Jr., indicating that substrate binding induces conformational changes in the enzyme, facilitating the reaction.

Coenzymes and Cofactors

• Coenzymes are organic molecules that assist enzymes and bind loosely to them.
• Cofactors can be inorganic or organic and assist in substrate recruitment without permanent binding.

Enzyme Nomenclature

• Enzyme names often end in -ase, derived from either the substrate (e.g., lactase from lactose) or the type of reaction (e.g., oxidase).
• The systematic nomenclature includes the EC number, indicating enzyme class, subclass, and specific enzyme identity.

Biological Enzyme Examples

• Lipase: Breaks down fats.
• Protease: Breaks down proteins.
• Cellulase: Breaks down cellulose.
• Amylase: Breaks down starch.
• Sucrase: Breaks down sucrose.
• Maltase: Breaks down maltose.
• Lactase: Breaks down lactose.

Factors Influencing Enzyme Action

• Concentration of substrates and enzymes affect reaction rates.
• Temperature and pH levels can optimize or hinder enzyme effectiveness.
• Presence of accelerators can enhance enzyme action, while inhibitors can slow it down or stop it.
• Environmental hazards may negatively impact enzyme function.