1 / 31

Cellular Respiration

This lecture outlines cellular respiration, including glycolysis, the Krebs cycle, electron transport, and chemiosmosis. It covers the production of ATP and the catabolism of carbohydrates, fats, and proteins. Background terms and concepts such as glucose, oxidation-reduction, and ATP are discussed. The lecture also highlights the energy flow and recycling in cellular respiration.

timothywilliams
Download Presentation

Cellular Respiration

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. Cellular Respiration Filename: Respire.ppt

  2. Lecture Outline • Using Chemical energy to drive metabolism • Production of ATP • Cellular respiration • Clycolysis • Krebs cycle • Electron transport • Chemiosmosis

  3. Lecture Overview • All organisms drive their metabolism with ATP generated from • Rearrangement of chemical bonds • Energetic electrons from proton pumps • Electrons from photosynthesis • Electrons from oxidation of sugars and fats

  4. Background Terms & Concepts • Glucose • Chemiosmosis • Oxidation- reduction • ATP • Exergonic vs endergonic reactions

  5. Concepts from OAC • Synthesis of ATP • Glycolysis: Krebs cycle • anaerobic vs aerobic glucose catabolism • Energy from fats & proteins

  6. Energy Flow & Recyling Energy Rich Energy Poor

  7. Cellular Respiration • Release of energy stored in organic compounds • Carbohydrate • Fats • Proteins (net energy loss) • Oxygen is consumed as a reactant • Carbon dioxide and water are byproducts • Energy is used indirectly • trapped as ATP

  8. Pathways in Cellular Respiration • Glycolysis • Krebs cycle • Electron transport chain Cellular Respiration Cumulative function of three metabolic pathways and chemiosmosis

  9. Catabolism of various foods

  10. Overview of Cellular Respiration A room of your own... ATP ATP ATP

  11. Glycolysis occurs whether or not oxygen is present

  12. Glycolysis • OCCURS in the CYTOPLASM • Glucose (6 carbon sugar) >>> 2 pyruvate (3 carbon sugar) • Energy investment phase • Energy yielding phase • Net yield of energy No Carbon dioxide is released during glycolysis

  13. Electron Transport System

  14. Glycolysis

  15. Glycolysis: Energy Investment • Glucose + ATP-> glucose-6-P + ADP • hexokinase • Glucose-6-P -> Fructose-6-P • phosphoglucoisomerase • Fructose-6-P + ATP -> Fructose 1,6, diphosphate + ADP • phosophofructokinase • Fructose 1,6,diphosphate -> glyceraldehyde phosphate + dihydroxyacetone phosphate • aldolase

  16. Energy Investment Phase

  17. ATP Investment More ATP investment

  18. Isomerization • glyceraldehyde phosphate &dihydroxyacetone phosphate are isomers • Isomerase interconverts • glyceraldehyde phosphate removed next as next step • THUS Equilibrium between the two sugars is in direction of glyceraldehyde phosphate

  19. Glycolysis: Energy Yield Phase • Glyceraldehyde-P + 2NAD+ +2Pi -> 1,3 glycerophosphate + 2 NADH + 2 H+ • !,3 glycerophosphate + 2ADP -> 3 phosphoglycerate + 2 ATP • Relocate phosphate group • Remove water to create phosphoenolpyruvate • Remove phosphate from PEP • PEP + 2ADP -> pyruvate + 2ATP

  20. Substrate level Phosphorylation The first payoff (substrate-level phosphorylation)

  21. More Energy Payoff More dividends (substrate-level phosphorylation)

  22. Glycolysis: Net Energy Yield • Glucose >>> 2 pyruvate • 2 ADP >>> 2 ATP • 2 NAD+ >>> 2NADH NADH>>> electron transport chain if oxygen is present

  23. Glycolysis Embden-Meyerhof Glucose>> glucose-6 phosphate Fructose-6 phosphate Fructose 1,6 diphosphate ISOMERS dihydroxyacetone phosphate Glyceraldehyde 3 P Alternate Enter-Doudoroff Glucose>> glucose-6 phosphate 6 phosphogluconic acid Keto deoxy 6 phoshogluconic acid pyruvic acid + Glyceraldehyde 3 P Alternate Glycolytic Pathway

  24. Pyruvate Oxidative phosphorylation Fermentation

  25. Role of Pyruvate

  26. Formation of Acetyl CoA • Pyruvate translocated from cytoplasm to mitochrondial matrix • Pyruvate + NAD+ -> Acetate + NADH + CO2 • Acetyl group attached to Coenzyme A Acetyl CoA links glycolysis to the Krebs cycle

  27. Formation of Acetyl CoA

  28. Krebs cycle • oxidation of pyruvate generated by glycolysis • glucose->2 pyruvate • Generates 1 molecule of ATP/ pyruvate • substrate level phosphorylation • Generates 4 molecules of NADH / pyruvate • Generates 1 molecule of FADH2/ pyruvate • Generate 3 molecules of carbon dioxide • OCCURS in MITOCHONDRIAL MATRIX • occurs in prokaryotic cytoplasm

  29. Krebs cycle

  30. IN Out IN IN Out Out Out IN Summary of Krebs Cycle

  31. Input Water ADP NAD+ FAD+ Acetyl CoA Output Carbon Dioxide ATP NADH FADH Krebs Cycle Balance Sheet

More Related