cellulose vs pectin

cellulose and pectin both are nouns.

Word	Noun	Adjective	Verb	Adverb
cellulose	Yes	No	No	No
pectin	Yes	No	No	No

As nouns, pectin is a hyponym of cellulose; that is, pectin is a word with a more specific, narrower meaning than cellulose:

cellulose: a polysaccharide that is the chief constituent of all plant tissues and fibers
pectin: any of various water-soluble colloidal carbohydrates that occur in ripe fruit and vegetables; used in making fruit jellies and jams

Other hyponyms of cellulose include carboxymethyl cellulose, DEAE cellulose, diethylaminoethyl cellulose, pulp.

cellulose (noun)	pectin (noun)
a polysaccharide that is the chief constituent of all plant tissues and fibers	any of various water-soluble colloidal carbohydrates that occur in ripe fruit and vegetables; used in making fruit jellies and jams