TAILIEUCHUNG - Lecture Biochemistry (2/e): Chapter 19 - Reginald Garrett, Charles Grisham

Glycolysis is a paradigm of metabolic pathways. Carried out in the cytosol of cells, it is basically an anaerobic process; its principal steps occur with no requirement for oxygen. Living things first appeared in an environment lacking O2, and glycolysis was an early and important pathway for extracting energy from nutrient molecules. It played a central role in anaerobic metabolic processes during the first 2 billion years of biological evolution on earth. | Chapter 19 Glycolysis to accompany Biochemistry, 2/e by Reginald Garrett and Charles Grisham All rights reserved. Requests for permission to make copies of any part of the work should be mailed to: Permissions Department, Harcourt Brace & Company, 6277 Sea Harbor Drive, Orlando, Florida 32887-6777 Outline Overview of Glycolysis Coupled Reactions in Glycolysis First Phase of Glycolysis Second Phase of Glycolysis Metabolic Fates of NADH and Pyruvate Anaerobic Pathways for Pyruvate Energetic Elegance of Glycolysis Other Substrates in Glycolysis Overview of Glycolysis The Embden-Meyerhof (Warburg) Pathway Essentially all cells carry out glycolysis Ten reactions - same in all cells - but rates differ Two phases: First phase converts glucose to two G-3-P Second phase produces two pyruvates Products are pyruvate, ATP and NADH Three possible fates for pyruvate First Phase of Glycolysis The first reaction - phosphorylation of glucose Hexokinase or glucokinase This is a priming reaction - ATP is consumed here in order to get more later ATP makes the phosphorylation of glucose spontaneous Be SURE you can interconvert Keq and standard state free energy change Be SURE you can use Eq. to generate far right column of Table Hexokinase 1st step in glycolysis; G large, negative Hexokinase (and glucokinase) act to phosphorylate glucose and keep it in the cell Km for glucose is mM; cell has 4 mm glucose So hexokinase is normally active! Glucokinase (Kmglucose = 10 mM) only turns on when cell is rich in glucose Hexokinase is regulated - allosterically inhibited by (product) glucose-6-P - but is not the most important site of regulation of glycolysis - Why? Rx 2: Phosphoglucoisomerase Glucose-6-P to Fructose-6-P Why does this reaction occur?? next step (phosphorylation at C-1) would be tough for hemiacetal -OH, but easy for primary -OH isomerization activates C-3 for cleavage in aldolase reaction Ene-diol intermediate in this .

• Sinh học
• Lecture Biochemistry
• Biological phenomena
• Living systems
• Structure of cells
• Coupled reactions in Glycolysis
• Energetic elegance of Glycolysis
• Principles of biochemistry
• Lecture Principles of biochemistry
• Biological systems
• Biochemical compounds
• Biological macromolecules
• Chemical principles
• Properties of water
• Hydrogen bonding
• Amino acids
• Amino acid structure
• Protein purification
• Cell extract
• Protein classification
• Protein 3 Dimensional structure
• Protein folding
• Protein 3 D structure
• 3 D structure
• Oxygen binding curve
• Enzyme kinetics
• Rate constants
• Catalytic Power
• Classes of enzymes
• Inhibitor kinetics
• Enzyme regulation
• Allosteric regulation
• Enzyme action
• Mechanisms of enzyme action
• Ions Cofactors
• Metal ion
• Nguyên lý hóa sinh
• Biotin cofactor
• Conformation of monosaccharides
• Carbohydrate classifications
• Oligo carbohydrate
• Polysaccharides carbohydrate
• Lipid subclasses
• Acyl lipids
• Fluid mosaic model
• membrane transporters
• Metabolism proceed
• Anaeorbic process
• Triose Phosphate Isomerase
• Regulation of glycolysis
• Control points in glycolysis
• Citric acid cycle
• TCA cycle
• Additional pathways
• Carbohydrate metabolism
• Electron transport
• Chemosmotic theory