Pyruvates
As pyruvate is known salts and esters of pyruvic acid .
Salts
The anion of pyruvic acid , pyruvate, is an important intermediate product in aerobic and anaerobic metabolism .
It arises, for example, in the cytoplasm of a cell when glucose is phosphorylated and broken down twice in the context of glycolysis .
The breakdown takes place via the intermediate products GAP and phosphoenolpyruvate .
In addition to 2 moles of pyruvic acid , the cell gains 2 moles of ATP and 2 moles of NADH + H + per mole of glucose . Pyruvate is an energy-rich compound and can be broken down further in the citric acid cycle (also called the citrate cycle , citric acid cycle , tricarboxylic acid cycle or Krebs cycle ). From the 2 moles of pyruvate obtained during glycolysis (from one mole of glucose), 6 moles of CO 2 , 8 moles of NADH + H + , 2 moles of FADH 2 and 2 moles of ATP are produced in the mitochondria of the cell . The transamination of pyruvate (reaction partner L - glutamic acid ) produces L - alanine (Ala) (see picture, A ). This connects to the metabolism of the amino acids (see glucose-alanine cycle , a variant of the well-known Cori cycle ). At the same time, pyruvate sets the course between entry via pyruvate carboxylase for gluconeogenesis ( B ) or entry into the citric acid cycle via pyruvate dehydrogenase multi - enzyme complex (energy deficiency situation, formation of acetyl-CoA ) ( C ). Under anaerobic conditions, however, it can also be metabolized to lactic acid or ethanol (see fermentation ).
In anaerobic formic acid fermentation, bacteria metabolize pyruvate to formic acid ( D ) with the help of formate acetyltransferase . In the first step of alcoholic fermentation , pyruvate is broken down into acetaldehyde in plants, fungi and some bacteria using pyruvate decarboxylase ( E ). With the help of lactate dehydrogenase (LDH), pyruvate can react to form lactate , which can be used in the anabolic and catabolic metabolism.
The metabolic product pyruvic acid is concentrated in serum and urine in the event of cell damage, for example of a toxic , hypoxic or hypovitaminotic type ; Likewise, glycogen depletion occurs in the liver and muscles .
Ester
Ethyl pyruvate is obtained by oxidizing ethyl lactate with potassium permanganate .