tear vs tear up

tear is a noun but tear up is not a noun.

Word	Noun	Adjective	Verb	Adverb
tear	Yes	No	Yes	No
tear up	No	No	Yes	No

As verbs, tear up is a hyponym of tear; that is, tear up is a word with a more specific, narrower meaning than tear:

Other hyponyms of tear include lacerate, pull, rend, rip, rive, rip up, shred.

tear (noun)	tear up (noun)
a drop of the clear salty saline solution secreted by the lacrimal glands
the act of tearing
an occasion for excessive eating or drinking
an opening made forcibly as by pulling apart

tear (verb)	tear up (verb)
separate or cause to separate abruptly	tear into shreds
to separate or be separated by force
strip of feathers
move quickly and violently
fill with tears or shed tears