Catabolism of

C. It is secreted along with noradrenaline by the adrenal medulla, from which it may be obtained. It may be synthesized from catechol. It is used as the acid tartrate in the treatment of allergic reactions and circulatory collapse. It is included in some local anaesthetic injections in order to constrict blood vessels locally and slow the disappearance of anaesthetic from the site of injection. Ultimately it induces cellular activation of phosphorylase which promotes catabolism of glycogen to glucose. 

Another unusual rearrangement is performed by Bacillus subtilis during the catabolism of sepiapterin (237), in converting the whole side-chain with subsequent oxidation of the pyrazine ring into 6-(l-carboxyethoxy)pterin (238 equation 75). 

The term fermentation is often used loosely by biochemical engineers. Biochemists have a more focused perspective (anaerobic) catabolism of an organic compound in which the compound serves as both an electron donor and acceptor and in which ATP is produced. 

Bacterial catabolism of oral food residue is probably responsible for a higher [NHj] in the oral cavity than in the rest of the respiratory tract.Ammonia, the by-product of oral bacterial protein catabolism and subsequent ureolysis, desorbs from the fluid lining the oral cavity to the airstream.. Saliva, gingival crevicular fluids, and dental plaque supply urea to oral bacteria and may themselves be sites of bacterial NH3 production, based on the presence of urease in each of these materials.Consequently, oral cavity fNTi3)4 is controlled by factors that influence bacterial protein catabolism and ureolysis. Such factors may include the pH of the surface lining fluid, bacterial nutrient sources (food residue on teeth or on buccal surfaces), saliva production, saliva pH, and the effects of oral surface temperature on bacterial metabolism and wall blood flow. The role of teeth, as structures that facilitate bacterial colonization and food entrapment, in augmenting [NH3J4 is unknown. 

The catabolism of amino acids provides pyruvate, acetyl-CoA, oxaloacetate, fumarate, a-ketoglutarate, and succinate, ail of which may be oxidized by the TCA cycle. In this way, proteins may serve as excellent sources of nutrient energy, as seen in Chapter 26. 

Animal cells obtain much of their energy from the breakdown (catabolism) of the six-carbon sugar glucose (C(,H, 0 ). The overall reaction for the catabolism of glucose is ... 

Look al the catabolism of my fistic acid shown in Figure 29.4 to see the overall results of the /3-oxidation pathway. The first passage converts the 14-carbon myristoyl CoA into the 12-carbon lauroyl CoA plus acetyl CoA, the second passage converts lauroyl CoA into the 10-carbon caproyl CoA plus acetyl CoA, the third passage converts caproyl CoA into the 8-carbon capryloyl CoA, and so on. Note that the final passage produces two molecules of acetyl CoA because the precursor has four carbons. 

Figure 29.4 Catabolism of the 14-carbon myristicacid by the 0-oxidation pathway yields seven molecules of acetyl CoA after six passages.

Problem 29.3 How many molecules of acetyl CoA are produced by catabolism of the following fatty acids, and how many passages of the )S-oxiclation pathway are needed ... 

Pyruvate, produced by catabolism of glucose (and by degradation of several amino acids), can undergo several further transformations depending on the conditions and on the organism. In the absence of oxygen, pyruvate can be either reduced by NADH to yield lactate [CHjCHfOHjCO - or, in yeast,... 

The catabolism of proteins is much more complex than that of fats and carbohydrates because each of the 20 amino acids is degraded through its own unique pathway. The general idea, however, is that the amino nitrogen atom is removed and the substance that remains is converted into a compound that enters the citric acid cycle. 

How many moles of acetyl CoA are produced by catabolism of the follow-ing substances ... 

How many grams of acetyl CoA (MW = 809.6 amu) are produced by catabolism of the following substances Which substances is the most efficient precursor of acetyl CoA on a weight basis ... 

Food, catabolism of, 1126-1128 Formal charge, 40-41 calculation of, 41-42 summary table of, 42 Formaldehyde, dipole moment of, 39 electrostatic potential map of. 167, 704... 

R)-Glyceraldehyde. Fischer projection of, 976 molecular model of, 976, 977 Glyceric acid, structure of. 753 Glycerol, catabolism of, 1132-1133 s/i-Glycerol 3-phosphate, naming of, 1132... 

Muscalure, structure of, 287 Mutarotation, 985-986 glucose and, 985-986 mechanism of. 986 Mycomycin, stereochemistry of, 330 Mylar, structure of, 819 n yo-Inositol, structure of, 135 Myrcene. structure of, 202 Mvristic acid, catabolism of, 1137 structure of. 1062... 

---