1 / 39

Carbohydrate Metabolism

Carbohydrate Metabolism. Aulanni’am Biochemistry Laboratory Chemistry Departement Brawijaya University. Carbohydrates. Carbohydrates are the most abundant organic molecules in nature Photosynthesis energy stored in carbohydrates;

tallys
Télécharger la présentation

Carbohydrate Metabolism

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Carbohydrate Metabolism Aulanni’am Biochemistry Laboratory Chemistry Departement Brawijaya University Aulani "Biokimia" Presentation 3

  2. Aulani "Biokimia" Presentation 3

  3. Carbohydrates • Carbohydrates are the most abundant organic molecules in nature • Photosynthesis energy stored in carbohydrates; • Carbohydrates are the metabolic precursors of all other biomolecules; • Important component of cell structures; • Important function in cell-cell recognition; • Carbohydrate chemistry: • Contains at least one asymmetric carbon center; • Favorable cyclic structures; • Able to form polymers Aulani "Biokimia" Presentation 3

  4. Carbohydrate Nomenclature • Carbohydrate Classes: • Monosaccharides (CH2O)n • Simple sugars, can not be broken down further; • Oligosaccharides • Few simple sugars (2-6). • Polysaccharides • Polymers of monosaccharides Aulani "Biokimia" Presentation 3

  5. Carbohydrate Nomenclature • Monosaccharide (carbon numbers 3-7) • Aldoses • Contain aldehyde • Name: aldo-#-oses (e.g., aldohexoses) Memorize all aldoses in Figure ? • Ketoses • Contain ketones • Name: keto-#-oses (ketohexoses) Aulani "Biokimia" Presentation 3

  6. Monosaccharide Structures Conformation of monosaccharide Conformation of glucose Aulani "Biokimia" Presentation 3

  7. Disaccharides • Simplest oligosaccharides; • Contain two monosaccharides linked by a glycosidic bond; • The free anomeric carbon is called reducing end; • The linkage carbon on the first sugar is always C-1. So disaccharides can be named as sugar-(a,b)-1,#-sugar, where a or b depends on the anomeric structure of the first sugar. For example, Maltose is glucose-a-1,4-glucose. Aulani "Biokimia" Presentation 3

  8. Structures of Disaccharides Note the linkage and reducing ends Aulani "Biokimia" Presentation 3

  9. Polysacchrides • Also called glycans; • Starch and glycogen are storage molecules; • Chitin and cellulose are structural molecules; • Cell surface polysaccharides are recognition molecules. • Glucose is the monosaccharides of the following polysacchrides with different linkages and banches • a(1,4), starch (more branch) • a(1,4), glycogen (less branch) • a(1,6), dextran (chromatography resins) • b(1,4), cellulose (cell walls of all plants) • b(1,4), Chitin similar to cellulose, but C2-OH is replaced by –NHCOCH3 (found in exoskeletons of crustaceans, insects, spiders) Aulani "Biokimia" Presentation 3

  10. Overview of Glucose Catabolism • Cells catabolize organic molecules and make ATP two ways: • Substrate-Level Phosphorylation • Glycolysis • Krebs (TCA) Cycle • Oxidative Phosphorylation • Electron Transport Chain Aulani "Biokimia" Presentation 3

  11. Overview of Glucose Catabolism Aulani "Biokimia" Presentation 3

  12. Overview of Glucose Catabolism • Net reaction • Glycolysis • Biochemical pathway that produces ATP by substrate-level phosphorylation. • Yields a net of two ATP molecules for each molecule of glucose catabolized. • Every living creature is capable of carrying out glycolysis. • Most present-day organisms can extract considerably more energy from glucose through aerobic respiration. Aulani "Biokimia" Presentation 3

  13. Glucose priming Aulani "Biokimia" Presentation 3

  14. P P Cleavage and rearrangement Aulani "Biokimia" Presentation 3

  15. Aulani "Biokimia" Presentation 3

  16. Aulani "Biokimia" Presentation 3

  17. Krebs Cycle • Cycle is also known as • Tricarboxylic acid (TCA) cycle • Citric acid cycle • After pyruvate has been oxidized, acetyl- CoA feeds into the Krebs cycle. • Krebs cycle is the next step of oxidative respiration and takes place in mitochondria. Occurs in three stages: • Acetyl-CoA binds a four-carbon molecule and produces a six-carbon molecule. • Two carbons are removed as CO2. • Four-carbon starting material is regenerated. citric acid Aulani "Biokimia" Presentation 3

  18. Aerobic Respiration • The pyruvic acid formed by glycolysis enters interior of mitochondria. • Converted by coenzyme A to 2 molecules of acetyl CoA and 2 C02. • Acetyl CoA serves as substrate for mitochondrial enzymes in the aerobic pathway. Aulani "Biokimia" Presentation 3

  19. Aulani "Biokimia" Presentation 3

  20. Aulani "Biokimia" Presentation 3

  21. Aulani "Biokimia" Presentation 3

  22. Aulani "Biokimia" Presentation 3

  23. Krebs Cycle • Generates two ATP molecules per molecule of glucose. • Generates many energized electrons which can be directed to the electron transport chain to drive synthesis of more ATP: • 6 NADH per molecule of glucose • 2 FADH2 per molecule of glucose Aulani "Biokimia" Presentation 3

  24. Aulani "Biokimia" Presentation 3

  25. Aulani "Biokimia" Presentation 3

  26. Aulani "Biokimia" Presentation 3

  27. Glycolysis Aulani "Biokimia" Presentation 3

  28. KREBS CYCLE • Takes place in Mitochondrion when oxygen is present • Pyruvic acid from glycolysis is trimmed to a 2 carbon compound • Remaining carbon from glucose => CO2 • Hydrogens transferred • NAD+ => NADH • FAD => FADH • Products of kreb cycle • 3 NADHs • 1 FADH2 • 2 ATP Aulani "Biokimia" Presentation 3

  29. The Cori Cycle • The reconversion of lactic acid to pyruvate sees the removal of fatiguing lactate from the site of production. • This forms the theoretical basis for the cool-down. • As the glycolysis pathway is reversible lactic acid can eventually be anabolised into glucose and stored in the liver, muscles or blood. Aulani "Biokimia" Presentation 3

  30. Electron Transport System Aulani "Biokimia" Presentation 3

  31. Electron Transport System Aulani "Biokimia" Presentation 3

  32. Energy • Capacity to performwork. • Two examples: 1. Kinetic energy 2. Potential energy Aulani "Biokimia" Presentation 3

  33. SUN Kinetic Energy • Energy in the process of doing work. • Energy of motion. • Examples: 1. Heat 2. Light energy Aulani "Biokimia" Presentation 3

  34. GAS Potential Energy • Energy that matter occupies because of it’s location, arrangement, or position. • Energy of position. • Examples: 1. Water behind a dam 2. Chemical energy (gas) Aulani "Biokimia" Presentation 3

  35. adenine phosphate group P P P ribose Question: Answer: • What isATP? • adenosine triphosphate (ATP) • Components: 1. adenine: nitrogenous base 2. ribose: five carbon sugar 3. phosphate group: chain of three Aulani "Biokimia" Presentation 3

  36. Answer: • Works by the direct chemical transfer of a phosphate group. • This is called “phosphorylation”. • The exergonic hydrolysis of ATP is coupled with the endergonic processes by transferring a phosphate group to another molecule. Aulani "Biokimia" Presentation 3

  37. Adenosine triphosphate (ATP) P P P Hydrolysis (add water) + P P P Adenosine diphosphate (ADP) Hydrolysis of ATP • ATP + H2O  ADP + P (exergonic) Aulani "Biokimia" Presentation 3

  38. Adenosine triphosphate (ATP) P P P Dehydration synthesis (remove water) + P P P Adenosine diphosphate (ADP) Dehydration of ATP ADP + P  ATP + H2O (endergonic) Aulani "Biokimia" Presentation 3

  39. thank you to be continued Aulani "Biokimia" Presentation 3

More Related