Celluar Respiration. Celluar respiration is the process by which cells acquire energy by breaking...
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Transcript of Celluar Respiration. Celluar respiration is the process by which cells acquire energy by breaking...
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
C6H12O6+6O2→6CO2+6H2O+E (38ATP)
requires O2 (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 O2
Pyruvate
Animal cell: lactate
Bacteria: an organic acid like lactate / EtOH
+ CO2
Yeasts: EtOH + CO2
is reduced into
2 ATPs
Disadvantage of fermentation
• End products: toxic to cells
blood can’t remove all lactate → muscle fatigue
O2 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