ch oline ). ▁However , ▁this ▁lip ase ▁exhib its ▁a ▁bro ader ▁substr ate ▁specific ity ▁than ▁simply ▁plate let ▁activ ating ▁factor . ▁Two ▁other ▁is o forms ▁of ▁int rac ell ular ▁plate let - activ ating ▁factor ▁ac et yl h yd rol ase ▁exist , ▁and ▁both ▁are ▁multi - sub unit ▁en zym es . ▁Additionally , ▁there ▁is ▁a ▁single - sub unit ▁ser um ▁is o form ▁of ▁this ▁en zym e . ▁ ▁References ▁ ▁Further ▁reading <0x0A> </s> ▁Z in berg ▁Gla cier ▁() ▁is ▁a ▁gla cier ▁in ▁east ▁Th ur ston ▁Island ; ▁it ▁flows ▁east - n ortheast ▁into ▁Morgan ▁In let ▁between ▁Tier ney ▁Pen ins ula ▁and ▁the ▁prom ont ory ▁ending ▁in ▁Ryan ▁Point . ▁N amed ▁by ▁Ad vis ory ▁Committee ▁on ▁Ant ar ctic ▁Names ▁( US - AC AN ) ▁after ▁C pl . ▁E . ▁Z in berg , ▁U . S . ▁Army ▁photograph er ▁in ▁the ▁Eastern ▁Group ▁of ▁U . S . ▁Navy ▁Operation ▁High j ump , ▁which ▁obtained ▁aer ial ▁photograph s ▁of ▁Th ur ston ▁Island ▁and ▁adjacent ▁coast al ▁areas , ▁ 1 9 4 6 – 4 7 . ▁ ▁See ▁also ▁ ▁List ▁of ▁gla ci ers ▁in ▁the ▁Ant ar ctic ▁ ▁Gla ci ology ▁ ▁Maps ▁ ▁Th ur ston ▁Island ▁– ▁Jones ▁Mountains . ▁ 1 : 5 0 0 0 0 0 ▁Ant arct ica ▁Sk etch ▁Map . ▁US