Confusion glycerol

Glycerin(e). Same as Glycerol or Glyceryl Trihydroxide. Not to be confused with glyceryl or propenyl, which.is trivalent radical, —H2C.CH.CH2—i -derived from glycerol... 

A second class of serpentine receptors are coupled through a G protein to a plasma membrane phospholipase C (PLC) that is specific for the plasma membrane lipid phosphatidylinositol 4,5-bisphosphate (see Fig. 10-15). This hormone-sensitive enzyme catalyzes the formation of two potent second messengers diacyl-glycerol and inositol 1,4,5-trisphosphate, or IP i (not to be confused with PIP3, p. 431). 

Cytochrome oxidase (cytochrome aa3) represents the most important cytochrome of the a class. This is the terminal oxidase used in animals, plants, yeasts, algae and some bacteria. It contains two copper centres, giving four redox groups in total. This oxidase is discussed with other cytochromes that have a terminal oxidase function in Sections 62.1.12.4 and 62.1.12.5. These are cytochromes o, d and cd,. The oxidases fed719 and ax are not included in that discussion. The situation regarding cytochrome ax has been confused, partly due to uncertainty in the definition of this cytochrome. In some respects, the properties of cytochrome ax resemble those of mitochondrial and bacterial aa3. It functions as a terminal oxidase in some bacteria,720 but its role in E. coli is unknown. A soluble fraction from disrupted E. coli cells grown anaerobically on glycerol and fumarate contains a hemoprotein similar to cytochrome ax, which has catalase and peroxidase activity.721... 

If more than one species of fatty acid is present, its relative location on the glycerol may be important to its functionality, enzyme susceptibility, and oxidation stability of the fat/oil. Several conventions have been developed to specify arrangements of fatty acids on the glycerol molecule (if known). To avoid confusion from inversion of the 1 and 3 carbon positions, hierarchies have been established to designate the number 1 carbon under... 

The term chemical chaperone has been proposed to describe small molecules such as glycerol, dimethylsulfoxide, and trimethylamine N-oxide that act as protein-stabilizing agents. This terminology is unfortunate and confuses students, because proteins are also chemicals. This term should be replaced by the term kosmotrope that physical chemists use to describe small molecules that stabilise proteins. 

The nomenclature of polar lipids is often confusing. In this chapter polar lipids with glycerol as the molecular backbone are referred to as phospholipids, and those derived from sphingosine - sphingolipids, and all lipids linked to any type of carbohydrate moiety - as glycolipids. Thus, in this chapter the term polar lipids refers to phospholipids, sphingolipids and glycolipids. 

These products are absorbed across the wall of the small intestine into the blood and are transported to cells. Once in the cells, glucose and other monosaccharides, fatty acids, some amino acids, and glycerol enter the mitochondria and feed into a complex series of reactions called the citric acid cycle, or Krebs cycle. The citric acid cycle produces carbon dioxide and other molecules, such as NADH (not to be confused with NADPH) and ATP. This NADH and ATP then move through another set of reactions to produce more ATP and water. 

The general term lipid includes fats, oils, and waxes. Fats are esters (alcohol and acid combinations) of glycerol and fatty acids that are solid at room temperature, while oils are glycerol esters that are liquid at room temperature. However, the term fats is often employed for both, to avoid confusion with essential oils and petroleum oils. Waxes are esters of fatty acids with alcohols other than glycerol. 

Lipoprotein lipase is activated by high levels of insulin. It acts to extract FAs and glycerol from chylomicrons in the circulation, which are taken up by the adipocytes and re-esterified into TAG to be stored. Insulin inactivates hormone-sensitive lipase to ensure that TAG is not degraded. (Be careful not to get the two enzymes confused.) In the fed state the brain and erythrocytes exclusively use glucose as their fuel supply. Muscle uses glucose as its main fuel, and is also able to metabolize branched amino acids (leucine, isoleucine and valine) as well. 

The Chemical Abstracts nomenclature is used for most of the acetals described in this chapter. The compounds are named either as dialkoxy derivatives or as derivatives of acetals or ketals. Confusion exists in the earlier literature on naming cyclic acetals. For example, the acetals prepared from glycerol and an aldehyde were at one time referred to as 1,2- or 1,3-alkylidene (or arylidene) glycerol however, today they are named as shown below ... 

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