The midgut of the tobacco hornworm (Manduca sexta) is a highly aerobic tissue that is destroyed and replaced by a pupal epithelium at metamorphosis. To determine how oxidative phosphorylation is altered during the programmed death of the larval cells, top-down control analysis was performed on mitochondria isolated from the midguts of larvae before and after the commitment to pupation. Oxygen c...

Enzymes that catalyze the oxidation of glucose and other sugars directly to the corresponding aldonic acids appear to be widely distributed in nature, since they have been found in bacteria (l-9)) fungi (10, II), algae (la), and animal tissue (13-15). In a preliminary communication (16), we have reported that the juice sacs of young oranges contain a system for the oxidation of sugars to aldoni...

Although it has long been known that microbes can generate energy using diverse strategies, only recently has it become clear that a growing number involve electron transfer to or from extracellular substrates. The best-known example of what we will term ‘extracellular respiration’ is electron transfer between microbes and minerals, such as iron and manganese (hydr)oxides. This makes sense, giv...

Oxidation was found to be efficiently coupled with phosphorylation in the liver mitochondria of the rat bearing Walker carcinoma 256. With succinate as substrate, the rates of oxidation and phosphorylation by the liver mitochondria of the tumor-bearing rat did not differ from the normal. The P:O ratios were 1.4 for the normal and 1.2 for the tumor-bearing rats. With j8-hydroxybutyrate as substr...

The properties of epitaxial silicene monolayers on Ag(111) at various levels of oxidation are determined through complementary density functional theory calculations and soft X-ray spectroscopy experiments. Our calculations indicate that moderate levels of oxidation do not cause a significant bandgap opening in the epitaxial silicene monolayer, suggesting that oxygen functionalization is not a ...

Enzymes that catalyze the oxidation of glucose and other sugars directly to the corresponding aldonic acids appear to be widely distributed in nature, since they have been found in bacteria (l-9)) fungi (10, II), algae (la), and animal tissue (13-15). In a preliminary communication (16), we have reported that the juice sacs of young oranges contain a system for the oxidation of sugars to aldoni...

Biphenyl dioxygenase is the enzyme that catalyzes the stereospecific dioxygenation of the aromatic ring. This enzyme has attracted the attention of researchers due to its ability to oxidize polychlorinated biphenyls, which is one of the serious environmental contaminants. We determined the crystal structure of the terminal oxygenase component of the biphenyl dioxygenase (BphA1A2) derived from R...

Ferrous sulphate, a waste product in titanium white production at the Chemical Plant "Police" S.A., was subjected to microbiological oxidation with Thiobacillus ferrooxidans bacteria. The kinetic parameters of the culture growth were calculated on the basis of the Monod equation. The process was found to be best described by the model of the autocatalytic 1st order reaction with respect to the ...

The study evaluated the interactions of puberty and obesity on substrate oxidation of overweight girls (n = 38) and boys (N = 35; BMI > 85th percentile) matched for gender, age, and puberty (pre/pubertal) with normal weight girls and boys. Metabolic rates (VO(2)) were obtained during rest and at 4, 5.6 and 8 k/h. Carbohydrate oxidation rates (mg/kgFFM/min) adjusted for % predicted VO(2max), wer...

We have studied metallic and oxidized chromium layers on thin ordered alumina films grown on a NiAl~110! substrate using x-ray photoelectron spectroscopy. The interaction between the chromium layers and the substrate has been characterized after deposition at room temperature and after oxidation at 300 and 700 K. Our results indicate partial oxidation of the deposited chromium with the fraction...