▁carri ers . ▁Z inc ▁ ions ▁are ▁used ▁to ▁stabil ize ▁the ▁z inc ▁finger ▁m ille u ▁of ▁many ▁DNA - binding ▁prote ins . ▁▁▁ ▁Period ▁ 4 ▁elements ▁can ▁also ▁be ▁found ▁complex ed ▁with ▁organ ic ▁small ▁mole cules ▁to ▁form ▁c of act ors . ▁The ▁most ▁famous ▁example ▁of ▁this ▁is ▁h eme : ▁an ▁iron - cont aining ▁por ph yr in ▁comp ound ▁responsible ▁for ▁the ▁o xygen - car ry ing ▁function ▁of ▁my og lo bin ▁and ▁hem og lo bin ▁as ▁well ▁as ▁the ▁catal yt ic ▁activity ▁of ▁cy to chrome ▁en zym es . ▁Hem oc yan in ▁rep laces ▁hem og lo bin ▁as ▁the ▁o xygen ▁car rier ▁of ▁choice ▁in ▁the ▁blood ▁of ▁certain ▁in verte br ates , ▁including ▁horses ho e ▁c rab s , ▁tar ant ulas , ▁and ▁oct op uses . ▁Vit amin ▁B 1 2 ▁represents ▁one ▁of ▁the ▁few ▁bio chem ical ▁applications ▁for ▁c ob alt . ▁ ▁References ▁ ▁Category : Period s ▁( period ic ▁table ) ▁Category : Pages ▁containing ▁element ▁color ▁directly <0x0A> </s> ▁El ▁có nd or ▁pas a ▁is ▁a ▁Per uv ian ▁z arz uela ▁( mus ical ▁play ) ▁whose ▁music ▁was ▁composed ▁by ▁Per uv ian ▁song writer ▁Daniel ▁Al om ía ▁Rob les ▁in ▁ 1 9 1 3 ▁with ▁a ▁script ▁written ▁by ▁Jul io ▁de ▁La ▁Paz ▁( pse ud onym ▁of ▁the ▁Lim en ian