Glucose Respiration inZygorhyncus moelleri;the Entry of Glucose into the Cells

Publisher Website
Google Scholar
Abstract
When glucose was added to carbohydrate-starved cells of Zygorhyncus, moelleri the rate of oxygen uptake did not immediately rise to a constant value, but there was a lag period of 2 or 3 hours before it reached its maximum level. The length of this lag period increased from a few minutes for short periods of starvation to 2–3 hours after 12 hours in a carbohydrate-free medium. Factors believed to affect cellular permeability (a cationic detergent, adjustments of the pH, and of the potassium/calcium ratio) reduced the length of the lag period by not more than 40 per cent. of the original value without affecting the final rate of oxygen uptake. Investigation of the entry of glucose into the cells showed that the rate of oxygen uptake was not limited by the concentration of intra-cellular glucose for more that about 11 per cent. of the lag period in starved cells. The reasons for this difference in the percentage of the lag period apparently due to a permeability barrier are tentatively discussed in connexion with the route by which glucose enters the cells.