Celluar respiration is the process by which cells acquire energy by breaking down nutrient molecules produced by photosynthesizers.
The law of conservation of energy: energy cannot be created or destroyed, but it can be changed from one form to another.
Food Nutrient molecules (such as Glucose) Energy ATP (Adenosine Triphosphate)
Cellular respiration A cellular process that breaks down carbohydrates and other metabolites with the concomitant buildup of ATP C 6 H 12 O 6 +6O 2 6CO 2 +6H 2 O+E (38ATP) requires O 2 (aerobic process) step-by-step metabolism to extract energy from glucose
ATP The common energy carrier of cells ADP (Adenosine Diphosphate) ATP P (phosphoric acid) energy
Fermentation An anaerobic process - occurs in the absence of O 2
Pyruvate Animal cell: lactate Bacteria: an organic acid like lactate / EtOH + CO 2 Yeasts: EtOH + CO 2 is reduced into 2 ATPs
Disadvantage of fermentation End products: toxic to cells blood cant remove all lactate muscle fatigue O 2 is needed to restore ATP levels and rid the body of lactate oxygen debit Efficiency: far less efficient than the complete breakdown of glucose 2 ATP / glucose = 14.6 kcal ~ 2.1% of cellular respiration (686 kcal)
Advantage of fermentation provides a quick burst of ATP energy for muscular activity Helps produce numerous food products Yeast Fermentation rises the dough rises bread produces EtOH wine and beer convert alcohol to acetic acid vinegar Bacterial Fermentation produces yogurt, sour cream, and cheese / pickled vegetables Yeast and fermenting bacteria added to soy beans and wheat soy sauce
Experiments 1.Respirometer Practice Page 80-81 2.Yeast Fermentation Page 82