Final answer:
Enzymes are the type of proteins responsible for facilitating or accelerating chemical reactions. They act as biological catalysts, are specific to substrates they work on, and are not consumed by the reactions they catalyze, enabling repeated usage.
Step-by-step explanation:
The type of protein that facilitates or accelerates chemical reactions is called an enzyme. Enzymes are macromolecules-most often proteins-that speed up chemical reactions by lowering activation energy barriers. They are very specific for the reactions they catalyze and are considered biological catalysts. Unlike inorganic catalysts that can work with a broad range of chemicals, enzymes are typically specific to particular substrates. An example of an enzyme is salivary amylase, which hydrolyzes its substrate amylose, a component of starch, thereby speeding up digestion.
Enzymes perform essential roles in controlling cellular metabolism and are not used or changed during the chemical reactions they catalyze. This means they can be used repeatedly. Their efficacy can be influenced by factors like pH levels, temperature, and the presence of other chemicals. Essentially, enzymes help in breakdown, rearrangement, or synthesis reactions within the body, being vital for processes such as digestion.