Copper is essential for our bodies to work properly. It is one of several micronutrients. These are minerals that are found in very small, but vital, quantities in our bodies.
It’s a slug’s life
Copper has another biological function in animals such as snails, lobsters and spiders. It is part of their blue blood!
Vertebrates (including humans) have red blood. The colour comes from a special molecule called haemoglobin, which is found in red blood cells. Haemoglobin carries oxygen around the body and its key element is iron.
On the other hand, some invertebrates rely on a molecule called haemocyanin to carry oxygen around their bodies. Snails, lobsters and spiders actually have blue blood (properly called haemolymph). The colour comes from the haemocyanin molecule, which is blue. It is dissolved directly into their ‘blood’ instead of being enclosed in blood cells.
Plants and crops, such as wheat, also need very small amounts of copper to grow. We say that it is a trace element in their diet. Their roots take in soluble copper compounds from the soil.
Putting the copper in
Only a small amount of copper in the soil is found in soluble compounds. However, as plants only need it in tiny amounts, there is usually enough for their needs. But farm animals feed on these plants. We say these animals are further up the food chain. The small amount of copper taken in by the plants is often not enough for normal growth in these animals. Copper is quite often added as a nutrient to feeds for cattle, pigs and poultry. This prevents deficiencies which reduce their growth.
In some parts of the country, not enough copper gets into the agricultural food chain through plants. Certain breeds of cattle and sheep are more likely to suffer from copper deficiency because of the grass they eat. To supplement their diet, farmers provide mineral licks, which contain essential elements such as copper.