AAs absorbed from the gastrointestinal tract along with those released within the body via body protein turnover can be used as a source of energy. The various AAs can be converted to either glycolytic or tricarboxylic acid (TCA) cycle intermediates and enter the respective pathway for energy production. Endogenous proteins undergo a continuous process of turnover (breakdown and synthesis). Approximately 85% of the AAs are reutilized for biosynthesis of proteins, with the remaining 12 to15% oxidized as energy.3 As shown in Figure 15.7, glycogenic (glucogenic) AAs can be converted to glucose. Some AAs can only be converted to acetyl-CoA. Consequently, they cannot be converted to glucose and can only be used for energy production or conversion to fatty acids or ketones. They are therefore commonly labeled ketogenic AAs. AAs capable of forming both glucose precursors and acetyl-CoA are sometimes called glyco-ketogenic.
Was this article helpful?
Discover secrets, myths, truths, lies and strategies for dealing effectively with cholesterol, now and forever! Uncover techniques, remedies and alternative for lowering your cholesterol quickly and significantly in just ONE MONTH! Find insights into the screenings, meanings and numbers involved in lowering cholesterol and the implications, consideration it has for your lifestyle and future!