A form of amylase found in the saliva of humans and some other animals.
- ‘The saliva of carnivora contains no ptyalin and cannot predigest starches; that of vegetarian animals contains ptyalin for the predigestion of starches.’
- ‘It begins in the mouth where the enzyme ptyalin, present in saliva, begins to break down starch in food to sugars.’
Mid 19th century: from Greek ptualon ‘spittle’ + -in.
We take a look at several popular, though confusing, punctuation marks.