Journal Feel the Burn Do you like to run, bike, or swim? These all are good ways to exercise. When you exercise, your body uses oxygen to get energy from glucose, a six-carbon sugar. Section How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run? 2.What do you think is happening in your cells to cause the changes in how you feel? 3.Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer.

Cellular Respiration …Is the reason we breath Oxygen in and Carbon Dioxide out

The process of releasing the energy from FOOD (glucose) to make ATP= Cellular Respiration

How is this formula similar to photosynthesis? ReactantsProducts C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy Glucose oxygencarbon water ATP, NADPH, FADH 2 dioxide Net reaction shown above A gradual release of energy from breaking down of glucose. This happens when there is oxygen present. If it released energy all at once all the energy would be lost as heat and light

Food (glucose) provides 1.Energy 2.Raw materials to build materials for growth and reproduction

Glucose Glycolysis Krebs cycle Electron transport Fermentation (without oxygen) Alcohol or lactic acid

Glucose (C 6 H ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO 2 ) + Water (H 2 O) Cellular Respiration

1 st step Glycolysis (makes 2 ATP) Glucose breaks down into 2 Pyruvic acidpyruvic acid - No oxygen required for this step - Occurs in cytoplasm of cell - pyruvic acid moves into mitochondria - Fast process, thousands in just a millisecond - Also makes 2 NADH

Cellular Respiration continues …IF oxygen is present in cell (this is why we must breath!) …continues to unlock energy not harvested in glycolysis (90%) still there High energy electrons still in pyruvic acid will be accepted by oxygen

Aerobic Respiration Kreb’s cycle (citric acid cycle) + Electron Transport Chain requires oxygen

Kreb’s cycle (citric acid cycle) makes 2 more ATP In mitochondria Pyruvic acid continues to break down Carbon atoms + oxygen CO 2 (into air) ADP 2 more ATP NAD+ NADH FAD FADH 2

Citric Acid Production

Electron transport chain makes 32 more ATP (similar to photosynthesis) High energy electrons move down electron transport chain (proteins in mitochondrian inner membranes) Those electrons help pump H+ out of matrix to create concentration gradient Then H+ diffuses back in membranes and makes… ATP via ATPsnythase (enzyme) LOTS OF ATP GENERATED LOW energy electrons + H+ + Oxygen H 2 O ( waste)

Electron Transport Hydrogen Ion Movement ATP Production ATP synthase Channel Electron Transport Chain

Total ATP production? With oxygen When one molecule of glucose breaks down… 2 glycolysis 2 Kreb’s + 32 Elec. Trans. 36 ATP from Cellular Respiration 38% efficient (better than standard car) 62% remaining, released as heat Remember: oxygen present

Glucose Glycolysis Cytoplasm Pyruvic acid Electrons carried in NADH Krebs Cycle Electrons carried in NADH and FADH 2 Electron Transport Chain Mitochondrion

Anaerobic Respiration - a different pathway Glycolysis still first (2ATP) If no oxygen available to cells

Anaerobic (w/o oxygen) In plants: Alcoholic fermentation Pyruvate + NADH alcohol + CO2 + NAD+ In animals: Lacitc Acid Fermentation Pyruvate + NADHlactic acid + NAD+ (accumulates in muscles) (sore muscles) (only removed with oxygen) (why we breath hard after race)

Compare Aerobic respiration Oxygen present 36 ATP total Generates 18X more ATP Anaerobic respiration No oxygen present Makes 2 ATP only Fermentation occurs

Our body uses both systems Quick Energy Sprints 1 st - uses small amts of ATP produced previously Use reserves of ATP for few seconds (50 meter dash) 2 nd - ATP produced by lactic acid fermentation - up to 90 seconds ( meters) Get rid of lactic acid with oxygen - breath harder after race Long Term energy After 90 seconds the only way to fuel activity is with CELLULAR RESPRIRATION Releases energy more slowly than fermentation so must pace yourself Glycogen supplies in cell last minutes Then use Fat (good for weight control)