1.The Nitrogen Cycle 2.Amino Acid Biosynthesis 3.Urea Cycle 4.Amino Acid Catabolism 5.Molecules Derived from Amino Acid (from Lehninger P )
The Nitrogen Cycle Page 810 nitrate nitrite nitrogenase Nitrite reductase Nitrate reductase
Nitrogen Fixation Is by Nitrogenase Complex Page 812
Three major reactions in all cells: 1.Carbamoyl-phosphate synthetase I NH 4 + +HCO ATP carbamoyl-phosphate +2ADP+P i +2H + 2.Glutamate dehydrogenase 3.Glutamine synthetase The Fate of Ammonium Page 815
The Glutamate Dehydrogenase Reaction Page 815
The enzymatic reaction catalyzed by glutamine synthetase Page 815
Two principal pathways : 1. The GDH/GS pathway 2.GS/GOGAT in organisms confronting N limitation (GOGAT is glutamate synthase or glutamate:oxo- glutarate amino transferase) The Major Pathways of Ammonium Assimilation Lead to Glutamine Synthesis Page 816
The GDH/GS Pathway of Ammonium Assimilation Page 816 GDH: glutamate dehydrogenase GS: glutamine synthetase
The GS/GOGAT Pathway of Ammonium Assimilation Page 817
The Subunit Organization of Bacterial Glutamine Synthetase Page 818
Glutamine Synthetase (GS) in E. coli is regulated in three ways: 1.Feedback inhibition 2.Covalent modification (interconverts between inactive and active forms) 3.Regulation of gene expression Page 817,818 & 820
Allosteric Regulation of Glutamine Synthetase by Feedback Inhibition Page 819
Covalent Modification of GS: Adenylylation of Tyr397 in the Glutamine Synthetase Page 819
The Covalent Modification of GS Page 820
Gene Expression Regulates GS Page 820
Amino Acids Are Formed from -keto Acids by Transamination Page 821
Human Dietary Requirements for Amino Acids Page 822
Amino Acid Biosynthesis Page 822
Chapter 25 Synthesis of Amino Acids in Bacteria
1 Page 822
Page 816 & 824
Urea cycle arginine Page 825
See page Page 822 & 831
Page 830
3 Pyruvate + glutamate Alanine + -KG Page 822 See P835 & P836
4 Page 822
Page 837
The Synthesis of S-adenosylmethionine (SAM) From Methionine Page 833
The Synthesis of S-adenosylmethionine (SAM) From Methionine Page 833
Page 822 5
Page 843 (also called Phenylalanine hydroxylase)
Some of the Aromatic Compounds Derived from Chorismate Page 841
Some of the Aromatic Compounds Derived from Chorismate Page 840
Page 842
Page 840 & 844 Histidine Biosynthesis and Purine Biosynthesis Are Connected by Common Intermediate
The Urea Cycle Page 827 Orithine transcarbamoylase Argininosuccinate synthetase Argininosuccinase arginase
Alanine Transports Ammonia from Muscles to the Liver
The TCA Cycle and Urea Cycle Can Be linked
Amino Acid Biosynthesis Inhibitors as Herbicides Page 838 *uncompetitive & noncompetitive inhibitor
Page 840 Overview of the Catabolism of Amino Acids in Mammals
Metabolic Degradation of the Common Amino Acids Page 841 & 845 Asn *glucogenic amino acid *ketogenic amino acid
Page 845
Page 848
Page 849 Maple syrup urine disease (楓漿尿病)
Page 849
Page 850
*Phenylketonuria(苯丙酮尿症) Page 843 & 848 Phenylalanine + -KG transaminase Phenylpyruvate + glutamate (phenylalanine hydroxylase) Aspatame
*Alkaptonuria (黑尿症) Page 850 Homogentisate dioxygenase
*Maple syrup urine disease (楓漿尿病) (page 846) *Alkaptonuria (黑尿症)(page 848) *Phenylketonuria(苯丙酮尿症)(page 848)
1.Ammonotelic 2.Ureotelic 3.Uricotelic Page 850
Biomolecules Derived from Amino Acid (from Lehninger P ) Page 854 & Porphyrins
Page 855
Page 856 Aged erythrocyte Jaundice 黄疸
Page Creatine
3.Glutathione Page 858
4.Neurotransmitters Page 859 & 860
4.Polyamines Page 860 & 861
5.Nitric Oxide
phosphodiesterase GMP Viagra 威而鋼 Soluble Guanylyl Cyclases Are Receptors for Nitric Oxide Stripped away (sildenafil)