Final answer:
Enzymes are biological catalysts that speed up reactions by lowering activation energy without being altered themselves. They function with high specificity and induce catalytic effects by optimizing substrate orientation, altering bond structures, providing conducive conditions, or participating directly in reactions.
Step-by-step explanation:
Enzymes can catalyze chemical transformations in biological systems without being altered themselves. These catalysts that occur naturally in living organisms work by accelerating chemical reactions at physiological temperatures through the reduction of activation energy. Enzymes, primarily proteins, have unique active sites made up of certain amino acid residues that create a specific chemical environment. This environment is essential in converting substrates into unstable intermediates, known as transition states. The binding between enzymes and substrates, with an induced fit, can catalyze reactions in four ways: by bringing substrates together in an optimal orientation, by compromising the bond structures of substrates, by providing optimal environmental conditions, or by participating directly in the chemical reaction. Importantly, enzymes operate with high specificity and do not alter the equilibrium of the reactions they catalyze, meaning they cannot change endergonic reactions to exergonic ones. They only facilitate the reactions to proceed at a much faster rate by lowering the energy barrier to reach the transition state.