Search results
Results from the WOW.Com Content Network
The ten-step catabolic pathway of glycolysis is the initial phase of free-energy release in the breakdown of glucose and can be split into two phases, the preparatory phase and payoff phase. ADP and phosphate are needed as precursors to synthesize ATP in the payoff reactions of the TCA cycle and oxidative phosphorylation mechanism. [ 4 ]
Schematic diagram showing anabolism and catabolism. Anabolism (/ ə ˈ n æ b ə l ɪ z ə m /) is the set of metabolic pathways that construct macromolecules like DNA or RNA from smaller units. [1] [2] These reactions require energy, known also as an endergonic process. [3] Anabolism is the building-up aspect of metabolism, whereas catabolism is
Oxidative phosphorylation in the eukaryotic mitochondrion is the best-understood example of this process. The mitochondrion is present in almost all eukaryotes, with the exception of anaerobic protozoa such as Trichomonas vaginalis that instead reduce protons to hydrogen in a remnant mitochondrion called a hydrogenosome .
Aerobic respiration requires oxygen (O 2) in order to create ATP.Although carbohydrates, fats and proteins are consumed as reactants, aerobic respiration is the preferred method of pyruvate production in glycolysis, and requires pyruvate be transported the mitochondria in order to be oxidized by the citric acid cycle.
Free guanine is salvaged in the same way except it requires hypoxanthine-guanine phosphoribosyltransferase. Defects in purine catabolism can result in a variety of diseases including gout, which stems from an accumulation of uric acid crystals in various joints, and adenosine deaminase deficiency, which causes immunodeficiency. [10] [11] [12]
Creatine kinase (CK), also known as creatine phosphokinase (CPK) or phosphocreatine kinase, is an enzyme (EC 2.7.3.2) expressed by various tissues and cell types.CK catalyses the conversion of creatine and uses adenosine triphosphate (ATP) to create phosphocreatine (PCr) and adenosine diphosphate (ADP).
The first step of this reaction is phosphorylation of the substrate via phosphotransferase during transport. In the case of glucose, the product of this phosphorylation is glucose-6-phosphate (Glc-6P). Due to the negative charge of the phosphate, this Glc-6P can no longer freely leave the cell.
Besides the myokinase reaction, a high ATP consumption and low ATP reservoir also increases protein catabolism and salvage of IMP, which results in increased AMP and IMP. These two nucleotides can then enter the purine nucleotide cycle to produce fumarate which will then produce ATP by oxidative phosphorylation.