Exoenzymes:
In eukaryotic cells, exoenzymes are manufactured like any other enzyme via protein synthesis, and are transported via the secretory pathway. After moving through the rough endoplasmic reticulum, they are processed through the Golgi apparatus, where they are packaged in vesicles and released out of the cell. In humans, a majority of such exoenzymes can be found in the digestive system and are used for metabolic breakdown of macronutrients via hydrolysis. Breakdown of these nutrients allows for their incorporation into other metabolic pathways.
Endoenzyme:
An endoenzyme, or intracellular enzyme, is an enzyme that functions within the cell in which it was produced. Because the majority of enzymes fall within this category, the term is used primarily to differentiate a specific enzyme from an exoenzyme. It is possible for a single enzyme to have both endoenzymatic and exoenzymatic functions.
Example:Glycolytic enzymes,enzymes of Kreb's Cycle. enzymes are a type of protein that speed up chemical reactions in cells. enzymes are specific to the job they do. only molecules that are the correct shape can fit into the enzyme. this is called the lock and key model. enzymes work outside of the cell (extracellular enzymes) as well as inside the cell (intracellular enzymes) In most cases the term endoenzyme refers to an enzyme that binds to a bond 'within the body' of a large molecule - usually a polymer. For example an endoamylase would break down large amylose molecules into shorter dextrin chains. On the other hand, an exoenzyme removes subunits from the polymer one at a time from one end; in effect it can only act at the end ponts of a polymer. An exoamylase would therefore remove one glucose molecule at a time from the end of an amylose molecule.
Exo (extra) vs. Endo (intra)
intra (meaning --within) cellular enzymes are the common metabolic enzymes that are responsible for catalyzing all those processes we need in our cells---relaese of energy from glucose or carbohydrates, lipids, proteins replication of DNAsynthesis of proteins and hundreds of others(a really cool one is acetylcholinesterase--check it out)
extra (meaning outside) cellular enzymes are released by the cells after being packaged by the golgi body or released straight out the membrane to perform a job external to that cell (ie digestive enzymes of our own digestive system--salivary, peptic and pancreatic enzymes to name some general types).
Lodish, Harvey (2008). Molecular cell biology (6th ed., [2nd print.]. ed.). New York Freeman. ISBN 0716776014.
Andrews, Lary. "Supplemental Enzymes for Digestion". Health and Healing Research. Retrieved 9 December 2013.
