Intermediate products of energy metabolism

In cells, there are metabolic pathways – a kind of crossroads of mutual transformation of nutrients. These include the ``pyruvate dehydrogenase reaction'  (PDH), the ``Krebs cycle (KC) and the respiratory chain (DŘ). Three intermediates, acetyl-CoA, pyruvate' and NADH, have an important position in energy metabolism.

Creation

 * Pyruvate dehydrogenase reaction (PDH):The irreversibility of this reaction is the reason that glucose cannot be formed from the vast majority of fatty acids.
 * Degradation of amino acids:Lysine and leucine are degraded directly to acetyl-CoA, other amino acids are converted via pyruvate.
 * β-oxidation of fatty acids and degradation of ketone bodies.

Usage

 * The Krebs cycle, which is followed by the respiratory chain (and ATP production).
 * Synthesis of fatty acids and ketone bodies (with an excess of acetyl-CoA).
 * Cholesterol synthesis.

Creation

 * 1) Aerobic glycolysis.
 * 2) Lactate oxidation (catalyzed by lactate dehydrogenase).
 * 3) Degradation of some AKs.

Usage

 * Synthesis of acetyl-CoA (PDH).
 * Lactate synthesis – takes place during anaerobic glycolysis, the purpose of which is to regenerate reduced coenzymes NADH + H+ back to NAD+.
 * Alanine synthesis (catalyzed by alanine aminotransferase).
 * Synthesis of oxaloacetate (catalyzed by pyruvate carboxylase).
 * Gluconeogenesis.

Creation

 * 1) Aerobic glycolysis
 * 2) Pyruvate dehydrogenase reaction.
 * 3) Beta-oxidation of fatty acids.
 * 4) Krebs cycle.
 * 5) Oxidation of ethanol.

Usage

 * The respiratory chain and the formation of ATP.
 * Conversion of pyruvate to lactate.

Link

 * ws:Meziprodukty energetického metabolismu