When we feel cold, this metabolically active tissue launches into overdrive.

Cells that have a particularly low metabolic activity, such as lymphocytes, must be used in higher numbers than more metabolically active cells, so direct cell-to-cell comparisons are difficult.

These methods also allow the detection and identification of viable but nonculturable cells that are metabolically active but non-dividing.

Large amounts of free iron in the circulation will cause damage to critical cells in the liver, the heart and other metabolically active organs.

However, this paradox can be resolved if much of the volume of the organisms was not metabolically active.