What is Pepsin?
'''Pepsin''' is an [[enzyme]]. It acts on proteins in the [[stomach]], which has a low [[pH]] because of the [[Hydrochloric acid]]. It works best at a pH of about 1.5.<ref>{{cite web|url=http://www.worthington-biochem.com/introbiochem/effectspH.html|title=Effects of pH|accessdate=2010-04-29}}</ref> It will not work at a pH above 6. It was the first animal enzyme to be discovered. [[Theodor Schwann]] discovered it in [[1836]]. Pepsin is used to make [[cheese]]. ==References== {{reflist}} {{biology-stub}} [[Category:Metabolism]] [[Category:Enzymes]]