an investigation of the isotopic exchange ( turnover ) of carbon among the basic groups of organic substances of yeast biomass ( proteins , polysaccharides , lipids , free amino acids , carbohydrates , and organic aicds ) showed that in the presence of a carbon source and all the necessary nutrient elements in the logarithmic phase of growth of the culture , the bulk of the organic substances of the cell are extremely stable .
C0007009
carbon
C0013879
elements