Glucose, electron-transport rates

A compound which is a good choice for an artificial electron relay is one which can reach the reduced FADH2 active site, undergo fast electron transfer, and then transport the electrons to the electrodes as rapidly as possible. Electron-transport rate studies have been done for an enzyme electrode for glucose (G) using interdigitated array electrodes (41). The following mechanism for redox reactions in osmium polymer—GOD biosensor films has... 

Foyer CH and Lelandais M (1996) A comparison ofthe relative rates of transport of ascorbate and glucose across the thylakoid, chloroplast and plasmalemma membranes of pea leaf mesophyll cells. J Plant Physiol 148 391-398 Foyer CH, Rowell J and Walker D (1983) Measurement ofthe ascorbate content of spinach leaf protoplasts and chloroplasts during illumination. Planta 157 239-244 Foyer CH, Furbank R, Harbinson J and Horton P (1990) The mechanisms contributing to photosynthetic control of electron transport by carbon assimilation in leaves. Photosynth Res 25 83-100... 

As Otto Shape runs, his skeletal muscles increase their use of ATP and their rate of fuel oxidation. Fatty acid oxidation is accelerated by the increased rate of the electron transport chain. As ATP is used and AMP increases, an AMP-dependent protein kinase acts to facilitate fuel utilization and maintain ATP homeostasis. Phosphorylation of acetyl CoA carboxylase results in a decreased level of malonyl CoA and increased activity of carnitine palmitoyl CoA transferase I. At the same time, AMP-dependent protein kinase facilitates the recruitment of glucose transporters into the plasma membrane of skeletal muscle, thereby increasing the rate of glucose uptake. AMP and hormonal signals also increase the supply of glucose 6-P from glycogenoly-sis. Thus, his muscles are supplied with more fuel, and all the oxidative pathways are accelerated. 

The reticulocyte differs from the erythrocyte in that (1) it contains small amounts of DNA (2) it contains amounts of RNA nearly equal to those in the stem cell (3) it contains intact tricarboxylic acid cycle and electron transport chain and (4) it can synthesize protein, but at a rate much slower than that observed in the stem cell. Some other enzymes that are also present in erythrocytes have been claimed to have higher activities in reticulocytes. Such is the case for glucose-6-phosphate dehydrogenase, 6-phosphoglu-conic dehydrogenase, phosphohexose isomerase, transketolase, aldolase, and lactic dehydrogenase. 

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