Presentation on theme: "(Harvesting Chemical Energy) Glycolysis Fermentation Aerobic respiration."— Presentation transcript:
(Harvesting Chemical Energy) Glycolysis Fermentation Aerobic respiration
Glycolysis animation hill.com/sites/ /student_vie w0/chapter25/animation__how_glyco lysis_works.html hill.com/sites/ /student_vie w0/chapter25/animation__how_glyco lysis_works.html Redox Reaction Oxidation: loss of e - (glucose) Reduced: Gain of e - (Co 2 )
Takes place in the cytosol 1, 6 carbon molecule of glucose goes through a series of chemical reactions catalyzed by specific enzymes to produce 2, 3 carbon molecules of pyruvic acid. NAD + similar to NADP + NAD + carry electrons and Hydrogen ions (NADH)
1 Glucose2 Pyruvic acid 2 ATP 4 ATP 2 NAD + 2 NADH 4 ADP + 2Phospates Net 2 ATP
Organic Compound Glycolysis ATP no oxygenoxygen FermentationAerobic Respiration
Prokaryotes and protists in anaerobic habitats (mainly unicellular organisms) Does not produce ATP Many Fermentation pathways differ in the types of enzymes and final products produced Two most common produced are lactic acid and ethyl alcohol
Occurs in muscle cell when strenuous exercise causes muscle cells to use up all the oxygen available to them. They switch to anaerobic respiration and lactic acid builds up in the cells, changing the acidity of the cytoplasm. Increased acidity decreases the cells ability to contract causing cramps and fatigue. Eventually it diffuses out of cell into blood stream and is transported to liver where it is converted back into pyruvic acid. Used to make cheese and yogurt
Used by some plants and unicellular organisms such a yeast Bread making
Requires O 2 Approximately 20 times as much ATP produced then glycolysis Two major stages: Krebs cycle and the electron transport chain In eukaryotic cell takes place in the mitochondria. Krebs cycle occurs in the mitochondrial matrix Electron transport chain occurs in the inner membrane
Pyruvic acid enters the mitochondrial matrix It reacts with a molecule called coenzyme A (CoA) to form acetyl CoA CO 2 and NADH and H + are produced
Step 1: Acetyl CoA combines with Oxaloacetic acid to form citric acid (regenerates CoA) Step 2: Citric acid releases CO 2 and a H atom that combines with NAD + to form NADH + H + to form 5 carbon compound. Step 3: 5 carbon compound releases CO 2 and a Hydrogen atom (combines with NAD + to form NADH + H + ) to form a 4 carbon compound. A molecule of ATP is formed.
Step 4: 4 Carbon compound releases a hydrogen atom ( combines with FAD to Form FADH 2 ) and is converted to another 4 carbon compound. Step 5: The 4 carbon compound releases a hydrogen atom and is (combines with NAD + to form NADH + H + )converted back into Oxaloacetic acid.
1 glucose molecule = 2 turns of the Krebs cycle 6 NADH 2 FADH 2 2 ATP 4 CO 2
Most of the energy from glucose still have not been transferred to ATP 10 NADH and the 2 FADH 2 produced so far to drive the electron transport chain