organic compounds + O 2 CO 2 + H 2 O + energy (ATP + heat). Feedback mechanisms control cellular respiration. Basic principles of supply and demand regulate the metabolic economy. If a cell has an excess of a certain amino acid, it typically uses feedback inhibition to prevent the diversion of intermediary molecules from the citric acid cycle to the synthesis pathway of that amino acid. The rate of catabolism is also regulated, typically by the level of ATP in the cell. If ATP levels drop, catabolism speeds up to produce more ATP. Control of catabolism is based mainly on regulating the activity of enzymes at strategic points in the catabolic pathway. One strategic point occurs in the third step of glycolysis, catalyzed by phosphofructokinase. Allosteric regulation of phosphofructokinase sets the pace of respiration.
This is the end of the preview. Sign up
access the rest of the document.