Primary pumping reaction

The absence of a complete population Inversion in the flash-initiated CFBr3 - SO2 system accounts for the weak CO laser intensity, compared with that detected in the CHBr3 - SO flash (18). In the CHBr3 - SOj system, the primary pumping reaction was assumed to be 0 + CH, which probably proceeds through the HCO complex with a shallower depth of about 20 kcal/ mole. The dynamics of this highly exothermic reaction (Ah° =... 

The term ion pump, synonymous with active ion-transport system, is used to refer to a protein that translocates ions across a membrane, uphill against an electrochemical potential gradient. The primary pumps do so by utilization of energy derived from various types of chemical reactions such as ATP hydrolysis, electron transfers (redox processes), and decarboxylations, or from the absorption of light (Table 1). Secondary pumps are symport and antiport systems that derive the energy for uphill movement of one species from a coupled downhill movement of another species. The electrochemical gradient driving the latter movement is often created by a primary pump. 

Fig. 5 The Primary Pump, a peptide-based protometabolism scenario [146] involving the following steps I amino acid N-carbamoylation II concentration through drying III NO -mediated CAA activation IV dissolution through watering (by e.g. sea water) V NCA reaction in aqueous phase (Va NCA hydrolysis Vb condensation with AA or peptide) VI slow hydrolysis of peptide bonds VII a-carbon epimerization (Vila of amino acid and CAA VNb of peptide residues). Additional steps corresponding to peptide N-carbamoylation/nitrosation have not been mentioned for the sake of clarity. It is worth mentioning that although the N-carbamoylation of peptides renders them unre-active towards NCA, this is reverted by NOx-mediated nitrosation [197], thus keeping peptides within the polymerization process...

The system s AHp should tall within the pump s primary or. secondary sweet zone. At the beginning of the operation, with the cold reactor vessel, the pump operates to the right of the BEP but within the. sweet zone, and as the reactor ve.s.sel is heated, the pump migrates on its curve toward the left, crossing the BEP, to the other extreme of its sweet zone. When the reaction is completed and the tank cools, the pump... 

There is a close kinship between the chemical process industry and the nuclear electric power industry. In tact once the physics of nuclear reaction was established the rest is chemistiy and hc.it ii an.sfer. The word "reactor" is from chemistry for the location the reaction takes place.. nuclear reactor consists of a vessel in which a nuclear reaction heats water to make steam to drive a turbine o generate electricity. Thus the primary components are pipes, valves, pumps heat exchangers, and water purifiers similar to the components found in a chemical plant. Following the success of WASH-1400, PSA was used to analyze the chemical proce.ssmg of nuclear fuel and. aste preparation for disposal. 

Alkanes and Alkenes. For this study, C150-1-01 and C150-1-03 were tested under primary wet gas conditions with ethylene, ethane, propylene, and propane being added to the feed gas. This study was made in order to determine whether these hydrocarbons would deposit carbon on the catalyst, would reform, or would pass through without reaction. The test was conducted using the dual-reactor heat sink unit with a water pump and vaporizer as the source of steam. All gas analyses were performed by gas chromatography. The test was stopped with the poisons still in the feed gas in order to preserve any carbon buildup which may have occurred on the catalysts. 

Fluorescence is not widely used as a general detection technique for polypeptides because only tyrosine and tryptophan residues possess native fluorescence. However, fluorescence can be used to detect the presence of these residues in peptides and to obtain information on their location in proteins. Fluorescence detectors are occasionally used in combination with postcolumn reaction systems to increase detection sensitivity for polypeptides. Fluorescamine, o-phthalaldehyde, and napthalenedialdehyde all react with primary amine groups to produce highly fluorescent derivatives.33,34 These reagents can be delivered by a secondary HPLC pump and mixed with the column effluent using a low-volume tee. The derivatization reaction is carried out in a packed bed or open-tube reactor. 

Fluorescence detection was selected to increase sensitivity and selectivity. Histamine has no natural fluorescence and a post-column derivatization with OPT was found to be facile. The OPT reaction with histamine or any primary amine will only occur in an alkaline medium. The derivatization reagent, pumped into the system after the mixture has been separated on the column, must be strongly basic to neutralize the acid in the mobile phase. The structure of the OPT adduct has been found to be dependent upon the pH at which the reaction is carried out as wel1 as the sol vent system (15). 

Active transport of a solute against a concentration gradient also can be driven by a flow of an ion down its concentration gradient. Table 17.6 lists some of the active-transport systems that operate in this way. In some cases, the ion moves across the membrane in the opposite direction to the primary substrate (antiport) in others, the two species move in the same direction (symport). Many eukaryotic cells take up neutral amino acids by coupling this uptake to the inward movement of Na+ (see fig. 17.26c). As we discussed previously, Na+ influx is downhill thermodynamically because the Na+-K+ pump keeps the intracellular concentration of Na+ lower than the extracellular concentration and sets up a favorable electric potential difference across the membrane. Another example is the /3-galactosidc transport system of E. coli, which couples uptake of lactose to the inward flow of protons (see fig. 17.26Proton influx is downhill because electron-transfer reactions (or,... 

---