Understanding Enzymes and Their Functions

Enzymes are proteins made of chains of amino acids folded into a specific three-dimensional

shape with an active site where substrates bind. They are named based on the reaction

they perform, usually ending in “-ase,” such as lactase or catalase. Enzymes are not

consumed in reactions; they can be reused repeatedly. Only specific substrates can bind to specific

enzymes because of the lock-and-key or induced-fit model, meaning the active site fits only certain

molecules. Enzymes belong to the protein class of macromolecules and are necessary

for all living things because they speed up biochemical reactions that would be too slow to support

life. Enzymes speed up reactions by lowering the activation energy needed for a reaction