Aerobic Cellular Respiration in Eukaryotes

Stage I: Glycolysis= "splitting of glucose"

- reactions occur in cytoplasm - series of 9 enzyme mediated biochemical reactions - net results: 1 molecule of glucose is oxidized to produce: 2 ATP- produced by substrate level phosphorylation 2 NADH- utilized in ETC 2 pyruvate (3C)- enter the matrix of mitochondria to start prep step

Stage III: Krebs Cycle

- reactions occur in matrix of mitochondria - series of enzyme mediated reactions in which acetyl is completely broken down into CO2, small amount of ATP and large amounts of NADH (=stored E) - for each turn of Krebs cycle, one acetyl replaces the 2C which are lost as CO2 during the cycle - since each molecule of glucose produces 2 molecules of acetyl the Krebs cycle must turn twice to oxidize one molecule of glucose; therefore the NET results per molecule of glucose oxidized is: 4 CO2 2 ATP- produced by substrate level phosphorylation 6 NADH 2 FADH2

Stage II: Prep Step:

- reactions occur in matrix of mitochondria - series of enzyme mediated reactions which: 1 molecule pyruvate is oxidized to 1 molecule of acetyl coenzyme A binds to acetyl -> acetyl-CoA 1 NADH is produced which is used in Stage IV 1 CO2 is produced which diffuses out of mitochondria, out of cell and out of organism Since 2 molecules of pyruvate enter this step one at a time, the NET results are 2 Acetyl-CoA 2 NADH 2 CO2

Four stages of aerobic respiration:

1. Stage I: glycolysis- takes place in cell cytoplasm 2. Stage II: Prep step to the Krebs cycle- takes place in matrix of mitochondria 3. Stage III: Krebs cycle- takes place in matrix of mitochondria 4. Stage IV: Electron transport chain- takes place in inner membrane of the mitochondria

NET ATP production of all 4 stages:

36 ATP

Aerobic respiration is ___% more efficient than anaerobic respiration (fermentation).

95

Aerobic respiration in prokaryotes occurs in the cytoplasm and on the folds of the cell membrane, NOT in mitochondria. Why?

?

Aerobic respiration occurs in plants and animals 24 hours per day.

true

In aerobic respiration oxygen is the final acceptor of electrons carried by NADH.

true