Fermentation

Cellular Respiration The respiration that we’ve discussed to this point has all relied on oxygen There are several types of respiration that can occur without oxygen These methods still rely on glycolysis to produce ATP, but create different waste products

What if oxygen is missing? No oxygen available = can’t complete aerobic respiration Cells can undergo: – Anaerobic respiration (also known as fermentation) – no oxygen or no mitochondria necessary (think bacteria) – can only make very little ATP – 2 Types: alcohol fermentation lactic acid fermentation large animals cannot survive long term using fermentation O2O2 yeast bacteria

Anaerobic Respiration lactic acid fermentation – Type of anaerobic fermentation that occurs in bacteria, animals – Uses: bacteria make yogurt animals feel muscle fatigue – General Process: glucose  ATP + lactic acid O2O2

Lactic acid fermentation Glucose->pyruvic acid -> 2ATP 2 lactic acid GLYCOLYSIS FERMENTATION used to make cheese and yogurt in humans during strenuous exercise when not enough oxygen is supplied from blood creating “oxygen debt” lactic acid accumulates in muscle; leads to fatigue and pain Will be converted back to pyruvic acid in liver

Anaerobic Respiration alcoholic fermentation – Type of anaerobic fermentation that occurs yeast – Uses: make beer, wine, bread – Process: glucose  ATP + CO 2 + alcohol O2O2

Alcoholic fermentation used by yeast cells and some bacteria to produce ATP, CO 2 and ethyl alcohol glucose -> pyruvic acid + 2ATP -> 2 CO2 +2 ethyl alcohol GLYCOLYSIS FERMENTATION GLYCOLYSIS FERMENTATION