Cellular Respiration

1. Cellular Respiration How do cells use food to make energy (ATP)? Chapter 9

2. Batteries of Life • Adenosine Triphosphate – ATP • Adenosine Diphosphate – ADP

3. ATP Adenine Ribose 3 Phosphate groups

4. Cellular Respiration • The process that releases energy by breaking down food molecules in the presence of oxygen • C6H12O6 + 6O2 -> 6H2O + 6CO2 + Energy

6. Main Types of Energy-Releasing Pathways Anaerobic pathways Evolved first Don’t require oxygen Start with glycolysis in cytoplasm Completed in cytoplasm Aerobic pathways Evolved later Require oxygen Start with glycolysis in cytoplasm Completed in mitochondria

7. 3 Steps - When Oxygen is Present • Glycolysis • Krebs Cycle (Citric Acid cycle) • Electron Transport Chain (Oxidative Phosphorylation)

8.  Cellular Respiration: An Overview Mitochondrion Electrons carried in NADH Electrons carried in NADH and FADH2 Pyruvic acid Glucose Electron Transport Chain Krebs Cycle Glycolysis Mitochondrion Cytoplasm

9.  Glycolysis Glucose 2 Pyruvic acid To the electron transport chain

10. Glycolysis • Glucose broken into 2 molecules of Pyruvic Acid • Oxygen not required • 2 ATP are used and 4 ATP and 2 NADH are produced • Occurs for a short time because NAD+ are used up

11. Krebs Cycle • When O2 is present, pyruvic acid from glycolysis produces CO2, ATP, NADH and FADH2. • 1 molecule of Glucose produces 2 turns of the cycle

12.  The Krebs Cycle Citric Acid Production Mitochondrion

13. Electron Transport Chain • NADH and FADH2 made in glyoclysis and the Krebs Cycle are used to make ATP • Oxygen accepts low energy electrons and H+ to form water. • ATP produced when H+ diffuses across the membrane

14. Electron Transport Chain Electron Transport Hydrogen Ion Movement Channel Mitochondrion Intermembrane Space ATP synthase Inner Membrane Matrix ATP Production

15. What does 1 molecule of glucose produce? • 36-38 ATP

16. How do we measure energy? • calorie- the amount of energy needed to raise the temp of 1 g of water 1 degree celsius. • IMPORTANT NOTE FOR YOUR LIFE • Food is labeled ___Calories/serving • Capital letter means Kilocalories = 1000 calories. • Package tells you how much energy the food can give you!

17. What happens when O2 isn’t available? • Fermentation • 2 Types • occurs after glycolysis • anaerobic - without oxygen • Alcohol Fermentation • Lactic Acid Fermentation

19. Alcohol Fermentation

20. Baking • Yeasts during this process release carbon dioxide which causes bread to rise

21. Lactic Acid Fermentation Lactic acid Glucose Pyruvic acid

22. The Burn • Large muscles that run out of oxygen quickly build up lactic acid which causes a painful burning sensation. • This occurs in animal cells

23. Quick Energy - Anaerobic • 4 seconds of ATP in the cell • 5 seconds - 90 seconds - Lactic Acid Fermentation • Oxygen debt and Heavy Breathing • Anaerobic training builds up glycogen in the muscles and develops lactic acid tolerance

24. NYC Marathon 2013 Geoffrey Mutai: winner for men: 2:08:07 PriscahJeptoo: winner for women 2:25:24

25. Long-Term Energy - Aerobic • Cellular Respiration after 90 seconds • Glycogen (Carbs) during the first 15-20 minutes • Fats after 20 minutes • Aerobic activity increases the size and number of mitochondria and increase oxygen delivery by improving the heart and lungs

26. Where does a runner get energy for a 5K race? • 1st- any available ATP • 2nd- glycolysis and lactic acid fermentation • 3rd- cellular respiration • Break down sugars • When out of sugars, break down fats • 4th- sometimes revert back to glycolysis and lactic acid fermentation if their body is not fit enough for the distance/terrain.

27. Where does your body “look” for energy? • 1. Carbs (Glucose for CR) • When out of carbs… • 2. Fats • When out of fats… • 3. Proteins • When out of proteins…you are dead.

28. Creatine • Creatine Phosphate donates a phosphate to ADP to make more ATP • Prolongs the 4 seconds before lactic acid fermentation • Allows for more repetitions and more intense workouts • If abused could lead to kidney and liver problems