Cellular Respiration Breaking down food to get energy

2 Basic Kinds of Respiration: Aerobic Uses O 2 to break down food Produces 38 ATP Anaerobic Takes place without oxygen Produces 2 ATP

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

If oxygen is present in cell… The next step of aerobic respiration occurs  The Krebs Cycle Pyruvate enters the mitochondria In a series of steps pyruvate is broken down into: 6 CO 2 molecules are released 2 ATP are made Electron carriers are made 3 NADH 1 FADH 2

The final step of aerobic respiration is the Electron Transport Chain ETC requires oxygen to work The electron carrier molecules (NADH and FADH 2 ) made in glycolysis and Krebs cycle are used to “power” the production of ATP Up to 34 ATPs can be made Water is made as a byproduct

Summing up Aerobic Respiration: Food, usually glucose, is broken down to make energy (ATP) 1 glucose molecule = up to 38 ATP molecules Oxygen is needed C 6 H 12 O O 2  6 CO H 2 O + ATP + Heat

If no oxygen is present… Some cells go through anaerobic respiration aka fermentation Since oxygen is required for the Krebs Cycle and for the Electron Transport Chain, the only part of cellular respiration that works without oxygen is glycosis which only produces a little ATP

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 Occurs in yeast Turn pyruvate into alcohol Breathe out CO 2 – makes bread rise Examples of Fermentation: