ANAEROBIC CELLULAR RESPIRATION EUKARYOTIC YEAST PROKARYOTIC INTESTINAL BACTERIA

2 TYPES OF CELLULAR RESPIRATION ANAEROBIC WITHOUT OXYGEN NO ATP PRODUCED ONLY UNICELLULAR ORGANISMS* INTESTINAL BACTERIA FOOD-POISONING BACTERIA: botulinum, e coli YEAST AEROBIC WITH OXYGEN ATP PRODUCED SOME UNICELLULAR/ ALL EUKARYOTES “SURFACE” BACTERIA ALL PROTISTS, FUNGI MULTICELLED PLANTS/ANIMALS * SOME COMPLEX ORGANISMS CAN UTILIZE AN ANAEROBIC PATHWAY, BUT, NOT FOR SUSTAINED ENERGY

GLYCOLYSIS BOTH ANAEROBIC AND AEROBIC RESPIRATION BEGINS WITH GLYCOLYSIS WORD ORIGIN: GLYCO: SUGAR LYSIS: TO BREAK IN THE CYTOPLASM ONE MONOSACCHARIDE(GLUCOSE) IS SPLIT INTO 2 – 3 CARBON MOLECULES OF PYRUVATE (PYRUVIC ACID) 4 ATP ARE PRODUCED, HOWEVER, 2 ATP ARE REUSED TO RUN GLYCOLYSIS SO THIS PROCESS YIELDS 2 NET ATP FOR CELLULAR FUNCTIONS PYRUVATE THEN ENTERS ONE OF THE TWO RESPIRATORY PATHWAYS 4 2 ATP

THE ANAEROBIC PATHWAY Since no ATP is produced, only unicellular organisms can utilize this pathway for sustained energy Following glycolysis, pyruvate enters the anaerobic pathway, if the organism does not use oxygen for its respiration Takes place in the cell membrane not mitochondria ( even if there is one ) Also called FERMENTATION LACTIC ACID FERMENTATION: lactate SOME BACTERIA MAMMAL MUSCLE ALCOHOL FERMENTATION: ethanol YEAST

ALCOHOL FERMENTATION Pyruvate is converted into ethanol by yeast CO 2 is released(this is why bread rises!) Very important to the bakery, beer/wine, biofuel industries

LACTIC ACID FERMENTATION Pyruvate is converted into lactate(lactic acid) by certain bacteria and mammal muscle Very important to the dairy industry in the production of yogurts, cheeses and sour cream

Lactic Acid Fermentation and Muscle When muscles are starved of oxygen, as happens during strenuous activity (or fight or flight) they temporarily convert pyruvate into lactate for energy. High levels of lactate(lactic acid) increases acidity in the muscle cells, creating a burning sensation. If this oxygen ‘debt’ is not replaced, ie by slowing down, the muscle will shut down, by cramping Cramping prevents damage to the muscle caused by the acid. Often soreness results. Eventually the lactic acid is metabolized by the liver So, when you FEEL THE BURN it means you are not using your muscles effectively. Workout to fatigue, but not burn!

THE ECONOMY OF FERMENATION