For 10 points, identify this element which is present biologically in both its +1 and +2 oxidation states and is symbolized Cu.
A defect in the ATP7A gene causes Menkes disease, which is an inability to metabolize this element. Though it is not cobalt, this element is being used in the SarAr technology for PET imaging, as its 64 isotope has a long half life, and Kayser-Fleischer rings occur around the cornea of the patients suffering from an inability to release this element into bile, also known as Wilson's Disease. It is also contained in Hemocyanin, which change color when oxygen binds to this element, and substitutes iron in the blood of the horseshoe crab. For 10 points, identify this element which is present biologically in both its +1 and +2 oxidation states and is symbolized Cu.
A defect in the ATP7A gene causes Menkes disease, which is an inability to metabolize this element.
{copper} (prompt on early: "Cu" buzz)