Final answer:
Enzymes are specialized proteins that act as biological catalysts, speeding up chemical reactions in living organisms by lowering the activation energy required for those reactions to occur.
Step-by-step explanation:
Enzymes are proteins that living things use as catalysts to speed up reactions. They perform the vital function of lowering the activation energies of chemical reactions inside cells, thereby allowing reactions that are essential for life to occur at a much faster rate than they would without the presence of these biological catalysts.
Enzymes work by providing an active site where specific reactants known as substrates can be bound and chemically transformed into products through various biological processes such as digestion, synthesis and metabolism. An example of an enzyme at work is salivary amylase which breaks down amylose a component of starch in our saliva.