Amino acid carbon dioxide

Septicaemia e g E.Coli, E.Coli 0157 H7, Staphylococcus Aureus, Amino acids. Carbon Dioxide, Glucose, O2, L-Glutamate, Lactose, Lactate, Oxalate, O2, Sucrose, Uric Acid, Urea etc. 

Potentiometric electrodes Ammonia or carbon dioxide gas sensing probes can be employed in the same way as the oxygen electrode, with the immobli-zed microbial layer held in place on the surface of the gas-permeable membrane. The ammonia probe is commonly used to determine amino acids by detection of ammonia production by microbial deamination of amino acids. Carbon dioxide probes are alternatives to oxygen electrodes for monitoring respiratory activity. 

On treatment of 5-amino- and 5-alkylamino-thiatriazoles with concentrated hydrochloric acid, formamidine disulfide dihydrochlorides (54) are formed, along with 50% hydrolysis leading to hydrazoic acid, carbon dioxide and hydrogen sulfide. It is postulated that hydrazoic acid reduces the positive ion presumably formed by ring cleavage of the thiatriazole in the presence of the strong acid (equation 26) (64AHC(3)263). 

FIGURE 8.10 Positions of entry of amino acid carbon skeletons into the Krebs cycle. Amino acids that are broken down to three-carbon skeletons may enter the Krebs cycle at the point of pyruvate. Glycine, after conversion to serine, can enter the Krebs cycle as pyruvate. Alternatively, glycine can be broken down by the glycine cleavage system (see Folate section). The products of this reaction are carbon dioxide and an ammonium ion. Five-carbon skeletons enter the Krebs cycle at the point of a-ketoglutarate, whereas four-carbon skeletons enter at the points of succinyl-CoA and oxaloacetic acid. 

The liver contains all the pathways for catabolism of all of the amino acids and can oxidize most of the carbon skeletons to carbon dioxide. A small proportion of the carbon skeletons are converted to ketone bodies. The liver also contains the pathways for converting amino acid carbon skeletons to glucose (gluconeo-genesis) that can be released into the blood. 

Benzoates. Dissolve 0-5 g. of the amino acid in 10 ml. of 10 per cent, sodium bicarbonate solution and add 1 g. of benzoyl chloride. Shake the mixture vigorously in a stoppered test-tube remove the stopper from time to time since carbon dioxide is evolved. When the odour of benzoyl chloride has disappeared, acidify with dilute hydrochloric acid to Congo red and filter. Extract the solid with a little cold ether to remove any benzoic acid which may be present. RecrystaUise the benzoyl derivative which remains from hot water or from dilute alcohol. 

The /-butoxycarbonyl group (Boc, "t-box ) has been eMens vely used in peptide synthesis, and Boc derivatives of many amino acids are commercially available. The customary reagent for the preparation from the amine is t-butyl azidoformate in water, dioxane/water, DMSO, or DMF. The cleavage by acids of medium strength proceeds with concomitant loss of isobutene and carbon dioxide (L.A. Carpino, 1957, 1973 see section 4.1.2.2). 

Other Reactions. a-Nitroalkanoic acids or thek esters can be prepared (54—56) by treating nitroparaffins with magnesium methyl carbonate, or with triisopropylaluminum and carbon dioxide. These products are reduced readily to a-amino acids. 

Manometric determiaation of L-lysiae, L-argioine, L-leuciae, L-ornithine, L-tyrosiae, L-histidine, L-glutamic acid, and L-aspartic acid has been reviewed (136). This method depends on the measurement of the carbon dioxide released by the T.-amino acid decarboxylase which is specific to each amino acid. 

Amino-2-hydroxybenzoic acid is manufactured by carboxylation of 3-amiaophenol under pressure with ammonium carbonate at 110 °C (182) or with potassium bicarbonate and carbon dioxide at 85—90°C (183) with subsequent acidification. 

The ammonium carbamate then loses a molecule of water to produce urea [57-13-6] CO(NH2)2- Commercially, this is probably the most important reaction of carbon dioxide and it is used worldwide ia the production of urea (qv) for synthetic fertilizers and plastics (see Amino resins Carbamic acid). 

Physiological Role of Citric Acid. Citric acid occurs ia the terminal oxidative metabolic system of virtually all organisms. This oxidative metabohc system (Fig. 2), variously called the Krebs cycle (for its discoverer, H. A. Krebs), the tricarboxyUc acid cycle, or the citric acid cycle, is a metaboHc cycle involving the conversion of carbohydrates, fats, or proteins to carbon dioxide and water. This cycle releases energy necessary for an organism s growth, movement, luminescence, chemosynthesis, and reproduction. The cycle also provides the carbon-containing materials from which cells synthesize amino acids and fats. Many yeasts, molds, and bacteria conduct the citric acid cycle, and can be selected for thek abiUty to maximize citric acid production in the process. This is the basis for the efficient commercial fermentation processes used today to produce citric acid. 

A hybridoma can live indefinitely in a growth medium that includes salts, glucose, glutamine, certain amino acids, and bovine serum that provides essential components that have not been identified. Serum is expensive, and its cost largely determines the economic feasibihty of a particular ciilture system. Only recently have substitutes or partial replacements for serum been found. Antibiotics are often included to prevent infection of the culture. The pH, temperature and dissolved oxygen, and carbon dioxide concentration must be closely controlled. The salt determines the osmotic pressure to preserve the integrity of the fragile cell. 

The alcoholic filtrate is evaporated to 50 cc., and 50 g. of barium hydroxide and 150 cc. of distilled water are added (Note 4). The mixture is refluxed for two hours and the excess barium hydroxide is precipitated with carbon dioxide. The barium carbonate is removed by filtration and washed with hot distilled water. A slight excess of sulfuric acid is added to the filtrate to liberate the amino acid from its barium salt, and an excess of barium carbonate is added to remove sulfate ion. The mixture is digested on the steam bath until effervescence ceases, and it is then filtered and the precipitate is washed with hot distilled water. The filtrate and washings are concentrated on the steam bath to a volume of 100 cc., decolorized with i g. of active carbon, filtered, and concentrated to the point of crystallization (about 25 cc.). The amino acid is precipitated by the addition of 150 cc. of absolute alcohol and the product is collected and washed with absolute alcohol. 

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