Aerobic vs. Anaerobic Respiration

Aerobic Energy Conversion Energy production that uses oxygen Ex. Cellular respiration Makes 38 ATP per glucose!!! Stage 2: Oxygen needed Stage 1: Oxygen not needed Stage 3: Oxygen needed Therefore…Overall Cellular respiration is an aerobic process

Why is O2 needed? Hydrogen atoms produced by reactions in the Krebs cycle and Electron Transport system are combined with oxygen to make water. With out oxygen these stages cannot occur 2 H+ + 1/2O2 --> H2O

Where does the oxygen come from? O2 from the air is collected in the lungs and transferred to the blood. The circulatory system delivers this blood to every cell in your body. Blood also carries away byproducts of cellular respiration Ex. CO2

What happens when the oxygen is used up? Oxygen supplies can be used up quickly through… Bursts of intense energy usage. Ex. Sprinting Extended exercise with little rest How did Protocol 1 from Lab 5-2 show this? Limited blood flow How did Protocol 4 from Lab 5-2 show this? Do muscles stop working when the oxygen is used up?

Anaerobic Energy Conversion Energy production that does not require oxygen. Lactic Acid Fermentation Enzyme-catalyzed reactions Includes glycolysis Occurs in cytoplasm of cells Produces ONLY 2 ATP! Produces Lactic Acid

Muscle Fatigue Build up of lactic acid in muscles results in the feeling of fatigue. Blood flow removes lactic acid from muscle cells (goes to the liver). Efficient circulatory systems remove lactic acid faster This is one reason for conditioning before competitions. (Getting “warmed up”)

Ethanol Fermentation Anaerobic energy conversion in Yeast Enzyme-catalyzed reactions Includes glycolysis Occurs in cytoplasm of cells Produces 2 ATP Produces Ethanol and CO2