The ionization behavior of cholic acid, deoxycholic acid, and chenodeoxycholic acid in a variety of physiologically important molecular environments was studied using 13C NMR spectroscopy. The apparent pKa of the carboxyl group was determined from titration curves obtained from the dependence of the carboxyl carbon chemical shift on pH. Using 90% 13C isotopic substitution of the carboxyl carbon...

It is well established that renal acid excretion can be influenced by certain tubular mechanisms that operate independently of systemic acid-base equilibrium. Thus, the stimulus for sodium reabsorption (1, 2), the competition between potassium and hydrogen ions for secretion (3), and the penetrating ability of anions present in the glomerular filtrate (4-6) are factors known to affect acid excr...

Purified preparations of cattle rhodopsin have been titrated to various pH, irradiated, and the pH changes followed thereafter until completed. In this way we have obtained the titration curves of rhodopsin, of the immediate product of irradiation, measured within 30 seconds; and of the final product of irradiation (opsin). The rhodopsin preparations display about 54 titratable groups per mole ...

It was a strange choice to ask me, who has not contributed to the description of the titration behavior of proteins, to discuss tha t subject. Nevertheless I am pleased to attempt to summarize the state of knowledge for our present purposes. Our best objective in this monograph is surely to make ourselves and each other better informed; we will be examining the meaning of terms for that purpose...

This study aimed to evaluate the effect of ascorbic and citric acids, blanching on stability Creole mango pulp, during freezing storage. We worked with scalded pulp (100 °C for two minutes) without blanching. Both pulps were treated acids in four combinations, packaged polyethylene bags, frozen stored at -18 90 days. During storage,the slightest browning occurred acidic not followed by pulp. Th...

background probiotics have been used for dairy products such as yogurt and yogurt drinks, however cholesterol content and lactose intolerance are important drawbacks. recently, consumption of non-dairy probiotic food especially for probiotic drink products has been intensified. objectives this research was conducted to determine the suitability of peach as a raw material for producing probiotic...

Crassulacean acid metabolism (CAM) is a CO2 acquisition, CO2 transient storage and CO2 concentrating mechanism based on organic acid synthesis. CO2 acquisition occurs in the dark. CO2 is fixed and stored in the form of organic acids. Remobilization of CO2 from the organic acids occurs in the light and leads to massive CO2 concentration inside photosynthesizing plant organs (green leaves or stem...