1. Chemical Pathways

2. Food is your source of energy! Calorie-amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius 1 kilocalorie is 1000 calories Kilocalories are actually on the food package but we call it CALORIES Cells use calories from food to make ATP Cellular energy Break off the phosphate molecules and we release energy Form ADP ADP is made back into ATP through cell respiration Plants and animals carrying out cell respiration.

3. Let’s watch a movie first. http://www.brainpop.com/science/cellularlife andgenetics/cellularrespiration/ Username: bcps Password: brainpop

4. Cell Respiration Overview Release energy by breaking down glucose and other food molecules with the help of oxygen Equation Oxygen + glucose= carbon dioxide + water+ ATP Take place in the mitochondria Two types of respiration: Anaerobic-does not use oxygen Aerobic-uses oxygen

7. Glycolysis Takes place in the cytoplasm of the cell INPUTS: Glucose and 2 molecules of ATP OUTPUTS: 4 ATP (net gain of 2) and pyruvic acid NADH holds electrons for later use to create tons of energy Called an electron carrier

8. Fermentation If oxygen is not present, fermentation takes place after glycolysis Fermentation-releases ATP from food without the use of oxygen Two main types Alcoholic fermentation-yeast form ethyl alcohol and carbon dioxide as waste; cause bread dough to rise Lactic acid fermentation-lactic acid is produced Created when your muscles do not have enough oxygen to produce ATP when exercising oBuildup of lactic acid creates a painful burning sensation Unicellular organisms use to make food like yogurt, cheese, sour cream, pickles, sauerkraut

11. Section 9.2 Kreb Cycle (citric acid cycle) Pathway is aerobic-needs oxygen to function Pyruvic acid from glycolysis enters the mitochondria Carbon is removed from this acid to form carbon dioxide Pyruvic acid will turn into acetyl CoA Acetyl CoA will turn into citric acid Citric acid goes through the cycle to form ATP, carbon dioxide, NADH and FADH2 (these two items hold high energy electrons that will be used in the next cycle)

12. Electron Transport Chain NADH and FADH2 is passed to this stage in the membrane of the mitochondria The electrons that are in these two molecules are passed along the carrier proteins in the membrane Water will form at the end of this chain Kreb and electron transport chain produce 36 ATP per one molecule of glucose

13. We don’t always consume glucose so how do we make ATP? Complex carbohydrates are broken down into glucose. Lipids and proteins can be broken down into molecules that enter the Kreb cycle and electron transport chain

14. Energy and exercise Quick energy Enough ATP for a short time Rest of time ATP is produced by lactic acid fermentation After race, heavy breathing is used to increase oxygen to repay the oxygen debt Long term energy For exercise that is 90 seconds or longer, body relies on cell respiration Use stored energy in the form of glycogen Body will begin to break down other stored molecules like fat