enzimes

Enzimes are biological catalysts that speed up chemical reactions in living organisms. Most are proteins, though some RNA molecules, known as ribozymes, also possess catalytic activity. Enzymes work by binding substrates at their active site, forming an enzyme-substrate complex that lowers the activation energy required for the reaction to proceed.

Enzyme specificity is high: each enzyme typically acts on a particular substrate or group of related substrates. The active site shape and its chemical environment determine compatibility. Many enzymes require cofactors such as metal ions or organic molecules (coenzymes) to assist in catalysis.

Enzymes are classified into six major categories by the Enzyme Commission: oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. They often rely on mechanisms like induced fit, where substrate binding induces conformational changes that enhance catalysis.

Kinetic properties of enzymes are described by Michaelis-Menten kinetics, using parameters such as Km and Vmax. Enzyme activity can be regulated by factors like temperature, pH, and inhibitors. Regulatory mechanisms include allosteric regulation and feedback inhibition that balance metabolic pathways.

Enzymes have wide applications in medicine, industry, and research. Digestive enzymes such as amylase, protease, and lipase aid digestion; DNA polymerase copies genetic material; many industrial enzymes are used in detergents, food processing, and biofuel production. Enzyme engineering and immobilization expand their practical use.