1. Energy and Life 1 Living things need energy to survive comes from food energy in most food comes from the sun Plants use light energy from the sun to produce food autotrophs organisms that make their own food Ex - plants heterotrophs organisms that must obtain energy from the foods they consume animals

2. 9-1 Chemical Pathways 2 Food serves as a source of raw materials for the cells in the body and as a source of energy. Animal Plant Animal Cells Plant Cells Mitochondrion

3. Chemical Energy and ATP 3 Energy – the ability to do work Forms: light, heat, electricity, chemical compounds chemical compound that cells use to store and release energy is adenosine triphosphate (ATP) ATP - basic energy source for all cells

4. Chemical Energy and ATP 4 ATP consists of: adenine ribose (a 5-carbon sugar) 3 phosphate groups Adenine ATP Ribose 3 Phosphate groups The three phosphate groups are the key to ATP's ability to store and release energy.

5. Chemical Energy and ATP 5 Storing Energy ADP has two phosphate groups instead of three. A cell can store small amounts of energy by adding a phosphate group to ADP. ADP ATP Energy Partially charged battery Fully charged battery + Adenosine Diphosphate (ADP) + Phosphate Adenosine Triphosphate (ATP)

6. Chemical Energy and ATP 6 Releasing Energy Energy stored in ATP is released by breaking the chemical bond between the second and third phosphates. P ADP 2 Phosphate groups

7. Chemical Energy and ATP 7 ATP energy uses: - cellular activities: active transport, protein synthesis - muscle contraction Most cells have only a small amount of ATP, because it is not a good way to store large amounts of energy. Cells can regenerate ATP from ADP as needed by using the energy in foods like glucose.

8. Cellular Respiration October 28, 2015 So what do our cells do with the Oxygen and why do they give off Carbon Dioxide? Answer: To make ATP!

9. October 28, 2015

10. Cellular Respiration October 28, 2015 C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + usable energy (ATP)

11. Cellular Respiration (3-stages) October 28, 2015 Glycolysis Krebs Cycle (Citric Acid Cycle) Electron Transport Chain (ETC)

12. Overview of Cellular Respiration 12 If oxygen is present: cellular respiration - the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen glycolysis  Krebs cycle  electron transport chain equation: 6O 2 + C 6 H 12 O 6 → 6CO 2 + 6H 2 O + Energy oxygen + glucose → carbon dioxide + water + Energy

13. Flowchart Section 9-2 Glucose (C 6 H 12 0 6 ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO 2 ) + Water (H 2 O) + ATP Cellular Respiration

14. October 28, 2015

15. Glucose To the electron transport chain Figure 9–3 Glycolysis Glycolysis: Step 1 2 Pyruvic acid

16. Glucose To the electron transport chain Figure 9–3 Glycolysis Section 9-1 2 Pyruvic acid

17. Glucose To the electron transport chain Figure 9–3 Glycolysis Section 9-1 2 Pyruvic acid

18. October 28, 2015 Where  Cytoplasm NO O 2 required Energy Yield  net gain of 2 ATP at the expense of 2 ATP 6-C glucose  TWO 3-C pyruvates Free e - and H + combine with organic ion carriers called NAD +  NADH + H + (nicotinamide dinucleotide)

19. Summary October 28, 2015 In Glucose (6-C) 2 ATP Out 2 pyruvate; 2(3-C) 2NADH a net of 2 ATP

20. October 28, 2015

21. Breakdown of Pyruvic Acid Where  mitochondria Pyruvate (3-C)  Acetic acid (2-C) 3rd C forms CO 2 Acetic acid combines with Coenzyme A to form ACETYL-CoA October 28, 2015

22. Citric Acid Production The Krebs Cycle Section 9-2 Mitochondrion

23. Krebs Cycle October 28, 2015

24. Second Step: Citric Acid Cycle (Krebs Cycle) October 28, 2015 Where  Mitochondrial matrix Energy Yield  2 ATP and more e - Acetyl-CoA (2-C) combines with 4-C to form 6-C CITRIC ACID Citric Acid (6-C) changed to 5-C then to a 4-C Gives off a CO 2 molecule NAD+ and FAD pick up the released e - FAD becomes FADH 2 NAD + becomes NADH + H + Cycle ALWAYS reforming a 4-C molecule

25. ETC October 28, 2015 Where  inner membrane of mitochondria Energy Yield  Total of 32 ATP O 2 combines with TWO H + to form H 2 O Exhale - CO 2, H 2 O comes from cellular respiration

26. Electron Transport Chain Section 9-2 Electron Transport Hydrogen Ion Movement ATP Production ATP synthase Channel Inner Membrane Matrix Intermembrane Space Mitochondrion

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

28. Aerobic vs. Anaerobic October 28, 2015 Anaerobic DOES NOT require oxygen Fast, but produces smaller amounts of energy (ATP) Aerobic requires oxygen Yields large amounts of energy