Triacylglycerols (fats) are the most abundant source of energy and provide energy twice as much as carbohydrates and proteins. This is achieved because the fatty acids which are present in the triacylglycerols are already in the reduced form. To convert fats into energy, the digested fats ( Read more on Digestion of Fats ) or the stored fats ( Read more about Mobilization and Cellular Uptake of Fats ) have to be first activated and transported ( Discussed in detail in Activation and Transportation of Fatty Acids via Carnitine shuttle ) to the mitochondrial matrix as all the enzymes required for metabolism (oxidation) are present there. For activation of fatty acids, they are converted to fatty acyl-CoA by the enzyme thiokinase in the cytosol and then with the help of carnitine ( L-carnitine is the active stereoisomer) is transported through the mitochondrial membranes into the mitochondrial matrix.
Phenols A class of chemical compounds perceptible in both aroma and taste. Some phenolic flavors and aromas are desirable in certain beer styles, for example German-style wheat beers in which the phenolic components derived from the yeast used, or Smoke beers in which the phenolic components derived from smoked malt. Higher concentrations in beer are often due to the brewing water, infection of the wort by bacteria or wild yeasts, cleaning agents, or crown and can linings. Phenolic sensory attributes include clovey, herbal, medicinal or pharmaceutical (band-aid).