Cellular Respiration - Brooklyn High School

Cellular Respiration Chapter 9 Cellular Respiration Process by which mitochondria break down food molecules to make ATP C6H12O6 + O2 CO2 + H2O + Energy Three Stages: Glycolysis Citric Acid Cycle (Krebs Cycle) Electron Transport Chain

Anaerobic vs. Aerobic Anaerobic Without oxygen Glycolysis, Fermentation Obligate Anaerobe Cannot survive in the presence of oxygen Tetanus Facultative Anaerobe Can use oxygen, but can survive in its absence

Yeast Aerobic Uses Oxygen Krebs and e- transport chain Produces a lot more energy Glycolysis Occurs in the cytoplasm of the cell Breaks down glucose ( 6-Carbon) into 2

pyruvic acid (3-Carbon) Makes 4 ATP, but uses 2 ATP = 2 ATP NAD+ accepts electrons to become NADH Those e- move to the e- transport chain Summary: Glycolysis makes 2 ATP, NADH, and 2 pyruvic acid. Citric Acid Cycle Begins after pyruvic acid is transformed into acetyl-CoA (this rxn also makes NADH) Occurs in the matrix of the mitochondria For every turn of the cycle the following are made:

1 ATP 2 CO2 3 NADH 1 FADH2 This cycle happens twice for each glucose Electron Transport Chain Located in the inner membrane of the mitochondria Similar to the e- transport chain in photosynthesis NADH and FADH2 supply the energized e ATP is produced and H+ is pumped into the

matrix of the mitochondria As the ATP moves out of the mitochondria more ATP is made Oxygen is the final e- acceptor at the end of the chain results in the formation of water Makes 32 ATP Summary of Cellular Respiration Glycolysis ATP

NADH 2 net (4 total) 2 Pyruvate 2 CO2

AcetylCoA Pyruvic acid to Acetyl-CoA Krebs (In 2 turns) 2 Electron Transport

Chain 32 6 FADH2 2 Other Products

CO2 H2O The 36 ATP produced in cellular respiration represent only about 38% of the energy stored in the sugar the rest of the energy is released as heat What if no oxygen is available? Glycolysis will continue, but if NAD+ is

not recycled it will stop, too. Less energy is produced only 2 ATP Fermentation cycles the NAD back to glycolysis, but does not produce energy Fermentation Lactic Acid Fermentation Makes lactic acid, CO2, and NAD+ Occurs in muscles when an oxygen debt is created

Alcoholic Fermentation Makes alcohol, CO2, and NAD+ Yeast and some bacteria