1. FERMENTATION: ANAEROBIC HARVESTING OF ENERGY © 2012 Pearson Education, Inc.

2. 6.13 Fermentation enables cells to produce ATP without oxygen  Fermentation is a way of harvesting chemical energy that does not require oxygen. Fermentation –takes advantage of glycolysis, –produces 2 ATP molecules per glucose, and –oxidizes NADH back to NAD +  Fermentation allows an anaerobic path for recycling NADH back to NAD +. © 2012 Pearson Education, Inc. Pyruvate (from glycolysis) Mitochondria (TCA and ETC) Cytoplasm (Fermentation) Little O 2 High O 2

3. Lactic Acid Fermentation  Animals and certain bacteria can oxidize NADH through lactic acid fermentation, in which –NADH is oxidized to NAD + and –pyruvate is reduced to lactate. © 2012 Pearson Education, Inc. Animation: Fermentation Overview 2 NAD  2 NADH 2 NAD  2 NADH 2 Lactate 2 Pyruvate Glucose 2 ADP 2 ATP 2 P Glycolysis

4. Alcohol Fermentation  The baking and winemaking industries have used alcohol fermentation for thousands of years.  In this process Yeasts (single- celled fungi) –oxidize NADH back to NAD + and –convert pyruvate to CO 2 and ethanol. © 2012 Pearson Education, Inc. 2 NAD  2 NADH 2 NAD  2 NADH 2 Ethanol 2 Pyruvate Glucose 2 ADP 2 ATP 2 P Glycolysis 2 CO 2

5. 6.14 EVOLUTION CONNECTION: Glycolysis evolved early in the history of life on Earth  Glycolysis is the universal energy-harvesting process of life.  The role of glycolysis in fermentation and respiration dates back to –life long before oxygen was present, –when only prokaryotes inhabited the Earth, –about 3.5 billion years ago. © 2012 Pearson Education, Inc.

6. 6.14 EVOLUTION CONNECTION: Glycolysis evolved early in the history of life on Earth  The ancient history of glycolysis is supported by its –occurrence in all the domains of life and –location within the cell, using pathways that do not involve any membrane-bounded organelles. © 2012 Pearson Education, Inc.

7. CONNECTIONS BETWEEN METABOLIC PATHWAYS © 2012 Pearson Education, Inc.

8. Cellular Respiration Pathways are Intersection between Catabolic and Anabolic reactions  Metabolism = sum total of chemical reactions occurring in an organism  Catabolism = Chemical reactions that break down molecules (energy releasing) –Ex: cellular respiration, hydrolysis of complex molecules  Anabolism = Chemical reactions that build up molecules (energy requiring) –Ex: photosynthesis, dehydration reactions to build macromolecules © 2012 Pearson Education, Inc.

9.  Glucose is primary fuel for respiration and fermentation, ATP can be generated using –carbohydrates –fats –Proteins  Fats yield more than 2x as much ATP per gram than carbs or protein –1 g carb = 4-5 Cal –1 g protein = 4-5 Cal –1 g fat = 10 Cal 6.15 Cells use many kinds of organic molecules as fuel for cellular respiration

10. Figure 2.2C

11. Sugars Glycerol Fatty acids Amino acids Amino groups Oxidative Phosphorylation Citric Acid Cycle Pyruvate Oxidation Acetyl CoA Glucose G3P Pyruvate Glycolysis Carbohydrates ATP Fats Proteins Food Catabolic Pathways

12. Fig. 7.12a

13. Carbohydrates Fats Proteins Cells, tissues, organisms Amino acids Fatty acids Glycerol Sugars Amino groups Citric Acid Cycle Pyruvate Oxidation Acetyl CoA ATP needed to drive biosynthesis ATP Glucose Synthesis Pyruvate G3PGlucose Anabolic Pathways Food molecules provide raw materials for biosynthesis Cells use intermediates from cellular respiration for the synthesis of other organic molecules.

14. 4 89 Stored 10 Stored 11 12 Krebs cycle 5 12 Pyruvate Acetyl-CoA Glycolysis 67 3