Cellular Respiration Cellular respiration takes the sugars from food and turns it into ATP. ATP is the energy currency of biological systems, and the energy stored in the bonds of ATP help the body carry out daily functions.

3 Stages of Cellular Respiration C6H12O6 + 6 O2  6CO2 + 6 H2O + ATP Glycolysis Pyruvate Oxidation and the Citric Acid Cycle (also known as the Krebs Cycle) Oxidative Phosphorylation

Stage 1: Glycolysis 1 Glucose  2 Pyruvate Occurs in the Cytoplasm Begins Cellular Respiration Forms ATP using Substrate-Phosphorylation Enzyme transfers a phosphate group from a substrate directly to ADP to form ATP. Happens in two stages Energy Investment Stage Energy Harvesting Stage

Stage 1: Glycolysis Energy Investment Stage Energy Harvesting Stage 1 Glucose  2 Glyceraldehyde-3-Phosphate (G3P) 2 ATP molecules are converted to ADP Energy Harvesting Stage 2 Glyceraldehyde-3-Phosphate (G3P)2 Pyruvate NAD+ reduced to NADH giving enough energy to attach phosphates to the G3P molecules 4 ADP molecules are converted to ATP The total process gains 2 ATP molecules Water is produced as a by-product Reduction is Adding electrons and Oxidation is removing electrons.

Stage 2: Pyruvate Oxidation and the Citric Acid Cycle Occur inside the Mitochondria. Pyruvate is oxidized in Pyruvate Oxidation to form a two-carbon molecule. The Citric Acid Cycle then completes the breakdown of Glucose to carbon dioxide. Forms ATP using Substrate-level Phosphorylation

Pyruvate Oxidation Pyruvate Acetyl Coenzyme A Pyruvate is transported into the mitochondria. Carboxyl Group is removed from Pyruvate and a molecule of CO2 is given off. Two-carbon molecule is oxidized while a molecule of NAD+ is reduced to NADH Coenzyme A joins with the two-carbon molecule to form Acetyl Coenzyme A, also called acetyl CoA

Citric Acid Cycle Two-Carbon Acetyl portion of Acetyl CoA enters the Citric Acid Cycle. Two-Carbon Acetyl group joins a four-carbon molecule that is processed through a series of redox reactions. Two CO2 molecules are removed, regenerating the four-carbon molecule. Each turn of the cycle makes 1 ATP (Substrate-level Phosphorylation), 3 NADH, and 1 FADH2

Stage 3: Oxidative Phosphorylation Final Stage of Cellular Respiration that provides the biggest energy pay off. Uses the election transport chain and chemiosmosis. Occurs in the inner membrane of the mitochondria where H+ concentration gradients are used to drive ATP Synthesis.

Electron Transport Chain NADH and FADH2 shuttle electrons to the Electron Transport Chain. Each Oxygen atom (½ O2) accepts 2 electrons and picks up 2 H+ to form H2O. Complexes I, III, IV use energy released from electron transfers to transport H2 across the membrane from an area of low concentration to an area of high concentration.

Chemiosmosis Uses the H+ transported across the membrane to power ATP Synthase. Moves H+ from High concentration to Low concentration to power ATP Synthase and convert ADP into ATP. Yields about 28 molecules of ATP per Glucose.

Cellular Respiration Overview C6H12O6 + 6 O2  6CO2 + 6 H2O + ATP Occurs in 3 stages Glycolysis (occurs in the Cytoplasm) Pyruvate Oxidation and Citric Acid Cycle (occurs in the mitochondria) Oxidative Phosphorylation (occurs across the membrane of the mitochondria) Produces a total of 32 ATP per Glucose Molecule.

Cellular Respiration Animation: http://www.mhhe.com/biosci/bio_animations/MH01_CellularRespiration_Web/index.html

Animation Cellular Respiration Animation-McGraw Hill (Resources Page)

Activity You are a mitochondria who has to train a new mitochondria how to make ATP through Cellular Respiration. Write out instructions for them of how to complete cellular respiration-be specific. Talk with your neighbor if you get stuck on part of the process and use your notes to help you out.