For this one, I will just give the bullet points from this paper (PDF)1. Zinc is Zn and Copper is Cu.
In blood plasma, Zn is bound to and transported by albumin (60%, low-affinity) and transferrin (10%). Since transferrin also transports iron, excessive iron can reduce zinc absorption, and vice-versa.
The concentration of zinc in blood plasma stays relatively constant regardless of zinc intake.
When copper is not present in sufficient quantities, the activity of superoxide dismutase is diminished, and the damage to cell membranes caused by superoxide radicals is increased. When functioning in this enzyme, copper works together with the mineral zinc, and it is actually the ratio of copper to zinc, rather than the absolute amount of copper or zinc alone, that helps the enzyme function properly.Several laboratory and human studies have found that high levels of supplemental zinc taken over extended periods of time may result in decreased copper absorption in the intestine, and copper deficiency with associated anemia. But some studies in humans suggest that high dietary Zn may not interfere with the actual tissue or plasma concentrations of Cu.Some experts believe that elevated copper levels, especially when zinc levels are also low may be a contributing factor in many medical conditions including schizophrenia, hypertension, autism, fatigue, muscle and joint pain, headaches, childhood hyperactivity, depression, insomnia, senility, and premenstrual syndrome.Adults taking copper supplements should also take zinc supplements (8 – 15 mg of zinc for every 1 mg of copper), because of an imbalance of these two minerals.Zinc deficiency is characterized by growth retardation, loss of appetite, and impaired immune function. In more severe cases, zinc deficiency causes hair loss, diarrhea, delayed sexual maturation, impotence, hypogonadism in males, and eye and skin lesions. Weight loss and impaired appetite, delayed healing of wounds, taste abnormalities, and altered cognition can also occur.Severe Zn deficiency depresses immune function, and even mild to moderate degrees of zinc deficiency can impair macrophage and neutrophil functions, natural killer cell activity, and complement activity. The body requires zinc to develop and activate T-lymphocytes. Individuals with low zinc levels have shown reduced lymphocyte proliferation response to mitogens and other adverse alterations in immunity that can be corrected by zinc supplementation.Acute adverse effects of high zinc intake include nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, and headaches. One case report cited severe nausea and vomiting within 30 minutes of ingesting 4 g of zinc gluconate . Intakes of 150–450 mg of zinc per day have been associated with such chronic effects as low copper status, altered iron function, reduced immune function, and reduced levels of high-density lipoproteins. Reductions in the superoxide dismutase levels, a marker of copper status, have been reported with even moderately high zinc intakes of approximately 60 mg/day for up to 10 weeks.Excessive copper intake can cause nausea, vomiting, abdominal pain and cramps, headache, dizziness, weakness, diarrhea, and a metallic taste in the mouth (assosiated with water containing copper concentrations greater than 6 mg/L). Chronic copper toxicity does not normally occur in humans because of transport systems that regulate absorption and excretion. Since excess copper is excreted through bile, copper toxicity is most likely to occur in individuals with liver disease or other medical conditions in which the excretion of bile is compromised.Also, copper and zinc are regarded as neurotransmitters and are in high concentrations in brain hippocampus. As a result elevated copper and depressed zinc have been associated with hyperactivity, attention deficit disorders, behavior disorders, and depression. Also, many of those labeled with autism and paranoid schizophrenia have elevated blood copper levels in addition to other biochemical imbalances. Elevated copper/zinc ratios can be especially serious for persons with low blood histamine. This combination of imbalances has been associated with anxiety, panic disorders, paranoia, and, in severe cases, hallucinationsSemen is particulary rich in Zn, which is a key factor in prostate gland function and reproductive organ growth. In the present study on rats, scientists observed changes in the testes after dietary zinc deficiency