Copper functions as a prosthetic group, which permits electron transfers in key enzymatic pathways like the electron transport chain. Copper is integrated in the enzymes cytochrome c oxidase, which is involved in cellular respiration and oxidative phosphorylation, Cu/Zn dismutase, which is involved in antioxidant defense, and many more listed in the table below. + Several Copper Dependent Enzymes and Their Function Group Enzyme Function Oxidases Flavin-containing amine oxidase Metabolism of neurotransmitters: noradrenaline, dopamine, serotonin and some dietary amines Protein-lysine-6-oxidase (lysyl oxidase) Connective tissue synthesis- cross-linking of collagen and elastin Copper-containing amine oxidase (a family of enzymes which includes primary-amine oxidase and diamine oxidase) Oxidation of biogenic amines including neurotransmitters, histamines, putrescine, cadaverine, and xenobiotic amines Cytochrome c oxidase Oxidative phosphorylation, electron transport in the mitochondrial membrane Superoxide dismutase (Cu/Zn dismutase) Antioxidant and free radical scavenger, oxidizes dangerous superoxides to safer hydrogen peroxide Ferroxidase I (ceruloplasmin) Iron transport-oxidation of Fe2+ to Fe3+, copper storage and transport, antioxidant and free radical neutralizer Hephaestin (ferroxidase) Iron transport and oxidation of Fe2+ to Fe3+ in intestinal cells to enable iron uptake Monooxygenases Dopamine beta-monooxygenase Conversion of dopamine to norepinephrine Peptidylglycine monooxygenase Peptide hormone maturation- amidation of alpha-terminal carboxylic acid group of glycine Monophenol monooxygenase (Tyrosinase) Melanin synthesis Methylation Cycle Methionine synthase Transfer of methyl group from methyltetrahydrofolate to homocysteine to generate methionine for the methylation cycle and tetrahydrofolate for purine synthesis Adenosylhomocysteinase (S-Adenosyl-L-homocysteine) Regeneration of homocysteine from adenosylhomocyesteine (S-Adenosyl-L-homocysteine) in the methylation cycle Neurological Cytochrome c Oxidase mechanism in mitochondrial membrane Cytochrome c oxidase There have been several hypotheses about the role of copper and some of its neurological manifestations. Some suggest that disruptions in cytochrome c oxidase, also known as Complex IV, of the electron transport chain is responsible for the spinal cord degeneration. Methylation cycle Myelinated neuron Another hypothesis is that<unk>  myelopathy is caused by disruptions in the methylation cycle. The methylation cycle causes a transfer of a methyl group (-CH3) from methyltetrahydrofolate to a range of macromolecules by the suspected copper dependent enzyme methionine synthase. This cycle is able to produce purines, which are a component of DNA nucleotide bases, and also myelin proteins. The spinal cord is surrounded by a layer of protective protein coating called myelin (see figure). When this methionine synthase enzyme is disrupted, the methylation decreases and myelination of the spinal cord is impaired. This cycle ultimately causes myelopathy. Hematological cause Iron transportation The anemia caused by<unk>  is thought to be caused by impaired iron transport. Hephaestin is a copper containing ferroxidase enzyme located in the duodenal muscosa that oxidizes iron and facilitates its transfer across the basolateral membrane into circulation. Another iron transporting enzyme is ceruloplasmin. This enzyme is required to mobilize iron from the reticuloendothelial cell to plasma. Ceruloplasmin also oxidizes iron from its ferrous state to the ferric form that is required for iron binding. Impairment in these copper dependent enzymes that transport iron may cause the secondary iron deficiency anemia. Another speculation for the cause of anemia is involving the mitochondrial enzyme cytochrome c oxidase (complex IV in the electron transport chain). Studies have shown that animal models with impaired cytochrome c oxidase failed to synthesize heme from ferric iron at the normal rate. The lower rate of the enzyme might also cause the excess iron to clump, giving the heme an unusual pattern. This unusual pattern is also known as ringed sideroblastic anemia cells. Cell growth halt The cause of neutropenia is still unclear; however, the arrest of maturing myelocytes, or neutrophil precursors, may cause the neutrophil deficiency. Zinc intoxication Zinc intoxication may cause anemia by blocking the absorption of copper from the stomach and duodenum. Zinc also upregulates the expression of chelator metallothionein in enterocytes, which are the majority of cells in the intestinal epithelium. Since copper has a higher affinity for metallothionein than zinc, the copper will remain bound inside the enterocyte, which will be later eliminated through the lumen. This mechanism is exploited therapeutically to achieve negative balance in Wilson’s disease, which involves an excess of copper.
Copper deficiency
Boron deficiency 
Fluorine deficiency
Copper toxicity
Biotin deficiency
Selenium deficiency
Zinc toxicity
Zinc deficiency