Presentation on theme: "Chapter 26 Amino Acids Metabolism. 26.1 Biosynthesis of Amino Acids Essential Amino Acids Ile Leu Lys Met Phe Thr Trp Val The amino acids can be grouped."— Presentation transcript:
26.1 Biosynthesis of Amino Acids Essential Amino Acids Ile Leu Lys Met Phe Thr Trp Val The amino acids can be grouped together into six biosynthetic pathways depending on the intermediate from which they are derived.
TCA CYCLE a-Ketoglutarate Oxaloacetate Glu Asp Gln Pro Arg Asn Met Thr Lys a-Ketoglutarate Ile family ( Glutamate family) Aspartate family
GLYCOLYSIS 3-Phosphoglycerate Pyruvate Ser Ala Val Leu Cys Gly Pyruvate family 3-Phosphoglycerate family ( Serine family)
PENTOSE PHOSPHATE GLYCOLYSISPATHWAY GLYCOLYSIS PATHWAY Phosphoenolpyruvate Erythrose 4-phosphate Ribose 5-phosphate Phe Tyr Trp His Phosphoenolpyruvate and Histidine Erythrose 4-phosphate family ( Aromatic family)
26.2 Amino Acid Degradation 26.2.1 The amino acids are degraded by 20 different pathways that converge to just 7 metabolic intermediates Pyruvate a-Ketoglutarate Succinyl-CoA Fumarate Oxaloacetate Acetyl-CoA Acetoacetate
26.3 Ammonia Excretion Glucose-alanine cycle IN MUSCLE NH 4 + + a-Ketoglutarate + NADPH + H + glutamate dehydrogenase Glu + NADP + + H 2 O alanine transaminase Glu + Pyruvate a-Ketoglutarate + Ala IN LIVER alanine transaminase Ala + a-Ketoglutarate Pyruvate + Glu
The excess nitrogen is first converted into ammonia and is the excreted from living organisms in one of three ways. Many aquatic animals simply excrete the ammonia itself directly into the surrounding water. Birds and terrestrial reptiles excrete the ammonia in the form of uric acid, while most terrestrial vertebrates convert the ammonia into urea before excretion. These three classes of organisms are called: ammonotelic, uricotelic and ureotelic, respectively.