Cellular Respiration Review C6H12O6 + 6 O2  6CO2 + 6 H2O + 32 ATP Happens in 3 Stages Glycolysis Pyruvate Oxidation and the Citric Cycle Oxidative Phosphorylation This process requires Oxygen. How can ATP be produced if Oxygen is not present?

Fermentation Fermentation is a way of harvesting chemical energy that does not require oxygen. Fermentation takes advantage of glycolysis, produces two ATP molecules per glucose, and reduces NAD+ to NADH. Fermentation provides an anaerobic path for recycling NADH back to NAD+.

Lactic Acid Fermentation 2 NAD 2 NADH 2 Lactate 2 Pyruvate Glucose 2 ADP 2 ATP 2 P Glycolysis Helps muscles regenerate NAD+. Pyruvate is reduced to form lactate. This process is used when the need for ATP outpaces the delivery of O2 from the bloodstream. Blood carries Lactate to the liver where it is converted back into pyruvate and oxidized.

Alcohol Fermentation 2 NAD 2 NADH 2 Ethanol 2 Pyruvate Glucose 2 ADP 2 ATP 2 P Glycolysis 2 CO2 Used by the baking and winemaking industries for thousands of years. In this process yeasts (single-celled fungi) oxidize NADH back to NAD+ convert pyruvate to CO2 and ethanol.

Types of Anaerobes Obligate Anaerobes Facultative Anaerobes Must be in anaerobic conditions and O2 is harmful. Found in stagnant ponds and deep in the soil. Facultative Anaerobes Can use Oxidative Phosphorylation or Fermentation depending on if O2 is available. Examples are yeast, some bacteria, and even our muscle cells can behave this way

Facultative Anaerobes The end of Glycolysis acts as a fork in the road for Facultative Anaerobes Oxidative Phosphorylation is used if oxygen is present Fermentation is used if oxygen is not present Aerobic Respiration is more productive. Anaerobic Fermentation- Bozeman (Resources Page) https://www.youtube.com/watch?v=cDC29iBxb3w

Lactic Acid Fermentation Examples Same in Both Alcohol Fermentation