The functions of minerals concern those functions performed by enzymes with the metals contained in them. In our search for clues to the guiding factors of increased bee mortality particular attention is drawn to two groups of enzymes:

•          The enzymes in the oxidative system: those containing iron, manganese, zinc or copper. These enzymes play a role in the energy system as well as the immune system.
•          The enzymes that break down proteins – the group of the metalloproteases – which usually contain manganese or zinc. These enzymes play a role in breaking down immune proteins.

In addition, the following points are significant:

•          In almost all cases, metal-containing or metal-dependent enzymes can be inhibited or deactivated by adding a strong chelate (EDTA). This will remove the metal group and the activity will no longer be present.
•          For certain enzymes in the oxidative system iron, manganese, copper and zinc are interchangeable (substitution). With this, enzyme activities adapt or the optimum pH changes, usually to a higher value.

One of the working hypotheses is that such changes occur in the oxidative system enzymes when the mineral supply via the pollen changes. In particular, it is thought that manganese plays a role when the availability of iron is reduced. This leads to changes in the energy supply for bees.