Celluar Respiration

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

Cellular respiration

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 can’t 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 Yeast Fermentation Page 82