“…A critical oxygen concentration of 0.02 mmolil has been observed for the present cell line (Backman and Wadso, 1991). This is in agreement with critical oxygen concentrations observed for, e.g., hepatocytes (0.01-0.02 mmolil), (Jones and Mason, 1978) and sheep lymphocytes (0.0002-0.02 mmolil), (Cheung and Morris, 1984). Apparent Michaelis-Menten constants for intact cells (e.g., Jones and Mason, 1978) are typically 10 times higher than for isolated mitochondria (Jones and Mason, 1978;Cole et al, 1982;Sugano et al, 1974) which is explained by intracellular diffusion gradients, presumably due to clustering of mitochondria (Jones, 1986).…”