Breaking down food to get energy Cellular Respiration Breaking down food to get energy

2 Basic Kinds of Respiration: Aerobic Uses O2 to break down food Anaerobic Takes place without oxygen

Glycolysis All types of respiration begin with glycolysis in the cytoplasm Glucose, a 6-C molecule, is split into 2 3-C molecules called pyruvate Energy is released: 2 ATP 2 NADH

If oxygen is present in cell… Pyruvate enters the mitochondria, the cell’s “powerhouse” In a # of steps called the Citric Acid Cycle, pyruvate is broken down 6 CO2 molecules are released 2 ATP are made Electron carriers are made (NADH and FADH2)

The final step of aerobic respiration is the Electron Transport Chain (ETC) ETC requires oxygen to work The carrier molecules made in glycolysis and Citric Acid cycle are used to “power” the production of ATP Up to 34 ATPs can be made Water is made as a waste

Summing up Aerobic Respiration: Food, usu. glucose, is broken down to make energy (ATP) Oxygen is needed C6H12O6 + 6 O2  6 CO2 + 6 H2O + ATP + Heat

If no oxygen is present… Some cells go through Fermentation Recycles necessary molecules that allow glycolysis to continue Only produces a little ATP

Examples of Fermentation: Lactic Acid Fermentation Occurs in Muscle cells Turn pyruvate into lactic acid when they run out of oxygen Lactic acid causes fatigue and cramping

Alcoholic Fermentation Yeast Turns pyruvate into alcohol- Wine Releases CO2 – makes bread rise