enzima

An enzima, known in English as an enzyme, is a biological molecule that acts as a catalyst to accelerate chemical reactions in living organisms. Most enzymes are proteins, though some ribonucleic acid molecules have catalytic properties and are called ribozymes. Enzyme action occurs at specific sites called active sites, where substrates bind, forming an enzyme-substrate complex that lowers the activation energy of the reaction.

Enzymes exhibit substrate specificity, often acting on particular substrates or reaction types. Many enzymes require non-protein helpers, such as cofactors (inorganic ions) or coenzymes (organic molecules), to function. Enzyme activity is influenced by environmental conditions like temperature and pH, and by regulatory molecules that can enhance or inhibit activity.

Kinetics and regulation: enzymes follow Michaelis-Menten kinetics; Km describes substrate affinity and Vmax the maximum rate. Inhibitors can be competitive, noncompetitive, or uncompetitive, and some enzymes are regulated by allosteric effectors, which change activity in response to cellular signals.

Examples and relevance: digestive enzymes such as amylase, protease, and lipase help break down carbohydrates, proteins, and fats. Other important enzymes include DNA polymerase, lactase, and catalase. Enzymes are essential in metabolism and are widely used in medicine and industry. Deficiencies or malfunctions in certain enzymes can cause disease; for example, lactase deficiency leads to lactose intolerance.