12.4.2
12.4.3
12.4.4
12.4.5
12.4.6
12.5
12.5.1
12.5.2
12.5.3
12.5.4
12.5.5
12.6
12.6.1
12.6.2
12.6.3
12.7
12.8
12.8.1
12.8.2
Aminotransferases
(Transaminases). . . . . . . . . . . . . . 415
Glutamate Dehydrogenases ...... 415
Glutamine Synthases
and Glutaminases ............ 417
Production of Ammonia . . . . . . . . 417
Urea Synthesis .............. 418
Metabolism of Individual Amino
Acids ..................... 421
Proline .................... 421
Sulphur-Containing Amino Acids .. 422
Serine .................... 424
Tryptophan. . . . . . . . . . . . . . . . . 424
Iodamino Acids. . . . . . . . . . . . . . 427
Aromatic Amino Acids and the
Sclerotization of Insect Cuticulae . . 428
Sclerotizing Substances . . . . . . . . . 429
The Process of Sclerotization . . . . . 430
Phenoloxidases . . . . . . . . . . . . . . 433
D-Amino Acids
and Their Metabolism. . . . . . . . . . 433
Amines ................... 434
N-Methylated Bases ........... 435
Amines Derived from Tyrosine,
Tryptophan and Histidine . . . . . . . 437
12.8.3 Polyamines ................. 438
12.9
Phosphagens and Other Guanidine
12.9.1
12.9.2
12.10
Compounds . . . . . . . . . . . . . . . . 439
Biosynthesis and Occurrence . . . . . 440
Phosphagen Kinases. . . . . . . . . . . 442
Oligopeptides
and Their Metabolism. . . . . . . . . . 444
12.10.1 Glutathione ................ 445
12.10.2 Histidine Peptides ............ 446
12.11 Purine and Pyrimidine
Compounds ................ 447
12.11.1 Biosynthesis of Purine
Nucleotides ................. 447
12.11.2 Adenylate and Guanylate
Cyclases. . . . . . . . . . . . . . . . . . . 449
12.11.3 Catabolism of Purine Nucleotides
and Uric Acid Synthesis ........ 450
12.11.4 Uricolysis .................. 452
12.11.5 Metabolism of Pyrimidine
Nucleotides ................. 453
References . . . . . . . . . . . . . . . . . 454
13
The Structure and Metabolism
of Carbohydrates. . . . . . . . . . . . 463
13.1
Sugars and Sugar Derivatives ..... 463
13.2
The Carbohydrate Spectrum of
Cells and Extracellular Fluids ..... 466
13.3
Metabolism of Low Molecular
Weight Carbohydrates. . . . . . . . . . 468
13.3.1
13.3.2
13.3.3
13.3.4
13.3.5
13.4
13.4.1
13.4.2
13.4.3
13.4.4
13.5
13.6
13.6.1
13.6.2
13.6.3
13.6.4
13.6.5
14
14.1
14.2
14.3
14.4
14.5
14.6
14.7
14.7.1
Contents
XV
The Main Metabolic Reactions of
Sugars .................... 469
Formation of Pentoses and NADPH
in the Pentose Phosphate Pathway .. 471
Biosynthesis of Fructose, Sugar
Alcohols and Glycerol. ......... 474
Ethanol Metabolism ........... 476
Biosynthesis of Ascorbic Acid ..... 479
Polysaccharides
and Proteoglycans . . . . . . . . . . . . 480
Glycosaminoglycans ........... 480
Glycan Sulphates
and Glycan Phosphates. . . . . . . . . 484
Chitin and Cellulose. . . . . . . . . . . 485
Glycogen, Galactan
and Other Reserve Polysaccharides. . 487
Glycoproteins . . . . . . . . . . . . . . . 489
Carbohydrases ............... 493
Glycosidases ................ 495
a-Amylases ................. 497
Digestion of Cellulose, Lichenin
and Laminarin ............... 499
Chitinolysis. . . . . . . . . . . . . . . . . 501
Lysozymes . . . . . . . . . . . . . . . . . 503
References . . . . . . . . . . . . . . . . . 505
Glycolysis . . . . . . . . . . . . . . . . 514
The Pathway from Hexose
to Pyruvate ................. 514
Glycogen Phosphorylases . . . . . . . 518
Hexokinases . . . . . . . . . . . . . . . . 522
Phosphofructokinases . . . . . . . . . . 525
Aldolases. . . . . . . . . . . . . . . . . . 527
Glyceraldehyde Phosphate
Dehydrogenases . . . . . . . . . . . . . 528
Pyruvate Kinases . . . . . . . . . . . . . 529
Pyruvate Kinase Isoenzymes
of Mammals . . . . . . . . . . . . . . . . 530
14.7.2 Pyruvate Kinase Isoenzymes
of Other Vertebrates ........... 531
14.7.3 Pyruvate Kinases of Invertebrates .. 531
14.8
Further Glycolysis Enzymes ...... 532
14.9
Gluconeogenesis ............. 534
14.10 Anaerobiosis ................ 535
14.10.1 Activity- and Habitat-Dependent
Anaerobiosis ................ 535
14.10.2 End Products of Anaerobic
Metabolism . . . . . . . . . . . . . . . . 537
14.11 Pyruvate Reductases ........... 541
14.11.1 Lactate Dehydrogenases
of Vertebrates . . . . . . . . . . . . . . . 542
14.11.2 Lactate Dehydrogenases
ofInvertebrates. . . . . . . . . . . . . . 545
14.11.3 Opine Dehydrogenases ......... 546
12.4.3
12.4.4
12.4.5
12.4.6
12.5
12.5.1
12.5.2
12.5.3
12.5.4
12.5.5
12.6
12.6.1
12.6.2
12.6.3
12.7
12.8
12.8.1
12.8.2
Aminotransferases
(Transaminases). . . . . . . . . . . . . . 415
Glutamate Dehydrogenases ...... 415
Glutamine Synthases
and Glutaminases ............ 417
Production of Ammonia . . . . . . . . 417
Urea Synthesis .............. 418
Metabolism of Individual Amino
Acids ..................... 421
Proline .................... 421
Sulphur-Containing Amino Acids .. 422
Serine .................... 424
Tryptophan. . . . . . . . . . . . . . . . . 424
Iodamino Acids. . . . . . . . . . . . . . 427
Aromatic Amino Acids and the
Sclerotization of Insect Cuticulae . . 428
Sclerotizing Substances . . . . . . . . . 429
The Process of Sclerotization . . . . . 430
Phenoloxidases . . . . . . . . . . . . . . 433
D-Amino Acids
and Their Metabolism. . . . . . . . . . 433
Amines ................... 434
N-Methylated Bases ........... 435
Amines Derived from Tyrosine,
Tryptophan and Histidine . . . . . . . 437
12.8.3 Polyamines ................. 438
12.9
Phosphagens and Other Guanidine
12.9.1
12.9.2
12.10
Compounds . . . . . . . . . . . . . . . . 439
Biosynthesis and Occurrence . . . . . 440
Phosphagen Kinases. . . . . . . . . . . 442
Oligopeptides
and Their Metabolism. . . . . . . . . . 444
12.10.1 Glutathione ................ 445
12.10.2 Histidine Peptides ............ 446
12.11 Purine and Pyrimidine
Compounds ................ 447
12.11.1 Biosynthesis of Purine
Nucleotides ................. 447
12.11.2 Adenylate and Guanylate
Cyclases. . . . . . . . . . . . . . . . . . . 449
12.11.3 Catabolism of Purine Nucleotides
and Uric Acid Synthesis ........ 450
12.11.4 Uricolysis .................. 452
12.11.5 Metabolism of Pyrimidine
Nucleotides ................. 453
References . . . . . . . . . . . . . . . . . 454
13
The Structure and Metabolism
of Carbohydrates. . . . . . . . . . . . 463
13.1
Sugars and Sugar Derivatives ..... 463
13.2
The Carbohydrate Spectrum of
Cells and Extracellular Fluids ..... 466
13.3
Metabolism of Low Molecular
Weight Carbohydrates. . . . . . . . . . 468
13.3.1
13.3.2
13.3.3
13.3.4
13.3.5
13.4
13.4.1
13.4.2
13.4.3
13.4.4
13.5
13.6
13.6.1
13.6.2
13.6.3
13.6.4
13.6.5
14
14.1
14.2
14.3
14.4
14.5
14.6
14.7
14.7.1
Contents
XV
The Main Metabolic Reactions of
Sugars .................... 469
Formation of Pentoses and NADPH
in the Pentose Phosphate Pathway .. 471
Biosynthesis of Fructose, Sugar
Alcohols and Glycerol. ......... 474
Ethanol Metabolism ........... 476
Biosynthesis of Ascorbic Acid ..... 479
Polysaccharides
and Proteoglycans . . . . . . . . . . . . 480
Glycosaminoglycans ........... 480
Glycan Sulphates
and Glycan Phosphates. . . . . . . . . 484
Chitin and Cellulose. . . . . . . . . . . 485
Glycogen, Galactan
and Other Reserve Polysaccharides. . 487
Glycoproteins . . . . . . . . . . . . . . . 489
Carbohydrases ............... 493
Glycosidases ................ 495
a-Amylases ................. 497
Digestion of Cellulose, Lichenin
and Laminarin ............... 499
Chitinolysis. . . . . . . . . . . . . . . . . 501
Lysozymes . . . . . . . . . . . . . . . . . 503
References . . . . . . . . . . . . . . . . . 505
Glycolysis . . . . . . . . . . . . . . . . 514
The Pathway from Hexose
to Pyruvate ................. 514
Glycogen Phosphorylases . . . . . . . 518
Hexokinases . . . . . . . . . . . . . . . . 522
Phosphofructokinases . . . . . . . . . . 525
Aldolases. . . . . . . . . . . . . . . . . . 527
Glyceraldehyde Phosphate
Dehydrogenases . . . . . . . . . . . . . 528
Pyruvate Kinases . . . . . . . . . . . . . 529
Pyruvate Kinase Isoenzymes
of Mammals . . . . . . . . . . . . . . . . 530
14.7.2 Pyruvate Kinase Isoenzymes
of Other Vertebrates ........... 531
14.7.3 Pyruvate Kinases of Invertebrates .. 531
14.8
Further Glycolysis Enzymes ...... 532
14.9
Gluconeogenesis ............. 534
14.10 Anaerobiosis ................ 535
14.10.1 Activity- and Habitat-Dependent
Anaerobiosis ................ 535
14.10.2 End Products of Anaerobic
Metabolism . . . . . . . . . . . . . . . . 537
14.11 Pyruvate Reductases ........... 541
14.11.1 Lactate Dehydrogenases
of Vertebrates . . . . . . . . . . . . . . . 542
14.11.2 Lactate Dehydrogenases
ofInvertebrates. . . . . . . . . . . . . . 545
14.11.3 Opine Dehydrogenases ......... 546