Insimbi iyinsimbi yoguquko ebaluleke kakhulu ezintweni eziphilayo. Endabeni yezilwane ezincelisayo, insimbi iyingxenye: I-Hemoglobin, i-transferrin, i-hemosiderin, i-myoglobin ne-ferritin. Lawa ngamaprotheni abalulekile ekuphileni. Ake sibone ukuthi iyini imisebenzi yayo ethile:
I-Ferritin : Isebenza njengendawo yokugcina insimbi ngaphakathi kweseli. Iyiprotheni enesisindo sama-molecule ephezulu kakhulu ekwazi ukugcina inani elikhulu lama-athomu e-Fe njenge-Fe3+. I-13% yensimbi kumuntu omdala ojwayelekile igcinwa ku-ferritin ngaphakathi kwamaseli futhi iyatholakala uma kudingeka.
I-TRANSFERRIN : iyiprotheni encibilikayo eplasma yegazi ephethe ukuthwala insimbi egayiwe isuka esiswini iye esitokisini.
I-Hemoglobin : Iqukethe u-65% we-iron ephelele yomzimba njenge-Fe2+ cation. I-Hemoglobin iyiprotheni ye-globular encibilika emanzini enomsebenzi wayo ukuthutha umoya-mpilo kuyi-plasma yegazi.
I-Myoglobin : Iqukethe u-6% wensimbi yomzimba futhi umsebenzi wayo ukunikeza umoya-mpilo emisipheni ukuze ikwazi ukwenza umsebenzi womshini (ukunyakaza).
I-Hemosiderin : Igcina u-12% we-iron iyonke emaseli omzimba.
Futhi amanye amaprotheni amaningi, njengama -enzyme athile , nawo aqukethe insimbi ekwakhekeni kwawo enemisebenzi ethile kakhulu ekusetshenzisweni komzimba womuntu.