biomass

biomassa The total mass of a living thing or part thereof, such as a cell.
2005, David A Guertin and David M Sabatini, chapter "Cell Size Control" in Encyclopedia of Life Sciences, Wiley:

Since protein constitutes the majority of the biomass of a cell, building new protein is a major way that cells increase their size.

In the untouched Shangri-la-like Kingman Reef in the Line Islands in the central Pacific, sharks make up 75 per cent of the fish biomass.