Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Chapter 15 lecture 1

243 views

Published on

Published in: Education
  • Be the first to comment

  • Be the first to like this

Chapter 15 lecture 1

  1. 1. Cellular Respiration Harvesting Chemical Energy 2006-2007 ATP
  2. 2. 2006-2007 What’s the point? The point is to make ATP ! ATP
  3. 3. Harvesting stored energy <ul><li>Energy is stored in organic molecules </li></ul><ul><ul><li>carbohydrates, fats, proteins </li></ul></ul><ul><li>Heterotrophs eat these organic molecules  food </li></ul><ul><ul><li>digest organic molecules to get… </li></ul></ul><ul><ul><ul><li>raw materials for synthesis </li></ul></ul></ul><ul><ul><ul><li>fuels for energy </li></ul></ul></ul><ul><ul><ul><ul><li>controlled release of energy </li></ul></ul></ul></ul><ul><ul><ul><ul><li>“ burning” fuels in a series of step-by-step enzyme-controlled reactions </li></ul></ul></ul></ul>
  4. 4. Harvesting stored energy <ul><li>Glucose is the model </li></ul><ul><ul><li>catabolism of glucose to produce ATP </li></ul></ul>CO 2 + H 2 O + heat RESPIRATION = making ATP (& some heat) by burning fuels in many small steps CO 2 + H 2 O + ATP (+ heat ) enzymes ATP C 6 H 12 O 6 6O 2 ATP 6H 2 O 6CO 2  + + + fuel (carbohydrates) COMBUSTION = making a lot of heat energy by burning fuels in one step ATP glucose glucose + oxygen  energy + water + carbon dioxide respiration O 2 O 2 + heat
  5. 5. How do we harvest energy from fuels? <ul><li>Digest large molecules into smaller ones </li></ul><ul><ul><li>break bonds & move electrons from one molecule to another </li></ul></ul><ul><ul><ul><li>as electrons move they “ carry energy ” with them </li></ul></ul></ul><ul><ul><ul><li>that energy is stored in another bond , released as heat or harvested to make ATP </li></ul></ul></ul>e - + – loses e- gains e- oxidized reduced redox e - e - + + oxidation reduction
  6. 6. How do we move electrons in biology? <ul><li>Moving electrons in living systems </li></ul><ul><ul><li>electrons cannot move alone in cells </li></ul></ul><ul><ul><ul><li>electrons move as part of H atom </li></ul></ul></ul><ul><ul><ul><li>move H = move electrons </li></ul></ul></ul>oxidation reduction e - p e + H + H + – loses e- gains e- oxidized reduced oxidation reduction C 6 H 12 O 6 6O 2 6CO 2 6H 2 O ATP  + + + H
  7. 7. Coupling oxidation & reduction <ul><li>REDOX reactions in respiration </li></ul><ul><ul><li>release energy as breakdown organic molecules </li></ul></ul><ul><ul><ul><li>break C-C bonds </li></ul></ul></ul><ul><ul><ul><li>strip off electrons from C-H bonds by removing H atoms </li></ul></ul></ul><ul><ul><ul><ul><li>C 6 H 12 O 6  CO 2 = the fuel has been oxidized </li></ul></ul></ul></ul><ul><ul><ul><li>electrons attracted to more electronegative atoms </li></ul></ul></ul><ul><ul><ul><ul><li>in biology, the most electronegative atom? </li></ul></ul></ul></ul><ul><ul><ul><ul><li>O 2  H 2 O = oxygen has been reduced </li></ul></ul></ul></ul><ul><ul><li>couple REDOX reactions & use the released energy to synthesize ATP </li></ul></ul>O 2 C 6 H 12 O 6 6O 2 6CO 2 6H 2 O ATP  + + + oxidation reduction
  8. 8. Oxidation & reduction <ul><li>Oxidation </li></ul><ul><ul><li>adding O </li></ul></ul><ul><ul><li>removing H </li></ul></ul><ul><ul><li>loss of electrons </li></ul></ul><ul><ul><li>releases energy </li></ul></ul><ul><ul><li>exergonic </li></ul></ul><ul><li>Reduction </li></ul><ul><ul><li>removing O </li></ul></ul><ul><ul><li>adding H </li></ul></ul><ul><ul><li>gain of electrons </li></ul></ul><ul><ul><li>stores energy </li></ul></ul><ul><ul><li>endergonic </li></ul></ul>C 6 H 12 O 6 6O 2 6CO 2 6H 2 O ATP  + + + oxidation reduction
  9. 9. Moving electrons in respiration <ul><li>Electron carriers move electrons by shuttling H atoms around </li></ul><ul><ul><li>NAD +  NADH (reduced) </li></ul></ul><ul><ul><li>FAD +2  FADH 2 (reduced) </li></ul></ul>NADH carries electrons as a reduced molecule reducing power! H like $$ in the bank + H reduction oxidation P O – O – O – O P O – O – O – O C C O NH 2 N + H adenine ribose sugar phosphates NAD + nicotinamide Vitamin B3 niacin P O – O – O – O P O – O – O – O C C O NH 2 N + H How efficient! Build once, use many ways
  10. 10. Overview of cellular respiration <ul><li>4 metabolic stages </li></ul><ul><ul><li>Anaerobic respiration </li></ul></ul><ul><ul><ul><li>1. Glycolysis </li></ul></ul></ul><ul><ul><ul><ul><li>respiration without O 2 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>in cytosol </li></ul></ul></ul></ul><ul><ul><li>Aerobic respiration </li></ul></ul><ul><ul><ul><ul><li>respiration using O 2 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>in mitochondria </li></ul></ul></ul></ul><ul><ul><ul><li>2. Pyruvate oxidation </li></ul></ul></ul><ul><ul><ul><li>3. Krebs cycle </li></ul></ul></ul><ul><ul><ul><li>4. Electron transport chain </li></ul></ul></ul>(+ heat ) C 6 H 12 O 6 6O 2 ATP 6H 2 O 6CO 2  + + +
  11. 11. 2006-2007 What’s the point? The point is to make ATP ! ATP
  12. 12. <ul><li>ATP synthase enzyme </li></ul><ul><ul><li>H + flows through it </li></ul></ul><ul><ul><ul><li>conformational changes </li></ul></ul></ul><ul><ul><ul><li>bond P i to ADP to make ATP </li></ul></ul></ul><ul><ul><li>set up a H + gradient </li></ul></ul><ul><ul><ul><li>allow the H + to flow down concentration gradient through ATP synthase </li></ul></ul></ul><ul><ul><ul><li>ADP + P i  ATP </li></ul></ul></ul>And how do we do that? ATP ADP But… How is the proton (H + ) gradient formed? H + H + H + H + H + H + H + H + H + P +
  13. 13. 2006-2007 H + ATP Got to wait until the sequel ! Got the Energy? Ask Questions ! H + H + H + H + H + H + H + H + ADP P +

×