Figure 2: Metabolic network model shows moderate accuracy in estimating amino acid consumption . (a) Model predictions compared well to experimental observations, given the scale of input data such as the consumption rates of glucose and lactate (upper right, filled circles). (b) The fold change of model predictions and experimental measurements was also explored. The mean and variance of fold change across all 10 clones and 8 timepoints are shown. Prediction accuracy was particularly good for phenylalanine, tryptophan and cysteine, whose fold change approached unity (red line, x-axis). However, for many amino acids, model predictions were prone to significant fold change errors. Notably, the relatively low variance in fold change error (y-axis) suggests that predictions could be improved empirically.