carotene vs provitamin

carotene and provitamin both are nouns.

Word	Noun	Adjective	Verb	Adverb
carotene	Yes	No	No	No
provitamin	Yes	No	No	No

As nouns, provitamin is a hypernym of carotene; that is, provitamin is a word with a broader meaning than carotene:

carotene: an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the liver
provitamin: vitamin precursor; a substance that is converted into a vitamin in animal tissues

carotene (noun)	provitamin (noun)
an orange isomer of an unsaturated hydrocarbon found in many plants; is converted into vitamin A in the liver	vitamin precursor; a substance that is converted into a vitamin in animal tissues
yellow or orange-red fat-soluble pigments in plants