2. Cellular Respiration -the breaking down of food molecules in the presence of oxygen to release energy C 6 H 12 O 6 + O 2 CO 2 + H 2 O ATP + (glucose) (energy)

3. Metabolism The set of chemical reactions in an organism’s cells that converts food into energy (ATP) “Burning calories” refers to how efficiently cells can perform cellular respiration More exercise = more energy required = more food required = faster metabolic rate

4. What is ATP? Molecule that is used as an energy source in the cell Produced in mitochondria Food molecules are needed to make ATP

5. ATP P Ribose Adenine 3 Phosphate groups PP

6. ATP P Ribose Adenine 3 Phosphate groups PP ENERGY stored in bonds

7. ATP PPP ADPADP ENERGY RELEASED P ATP

8. 3 Steps of Cellular Respiration (each produces some ATP) 1) Glycolysis - splitting of glucose (2 ATP) (anaerobic - no O 2 needed) 2) Citric Acid (Kreb’s) cycle (2 ATP) (aerobic - O 2 needed) 3) Electron transport chain (32-34 ATP) (aerobic) *steps 2 and 3 happen in mitochondria *step 1 happens in the cytoplasm outside the mitochondria

9. What happens without oxygen? Citric acid cycle and electron transport chain (ETC) cannot occur Glycolysis is followed by fermentation There are two types of fermentation: alcoholic and lactic acid See diagram

10. Glucose Glycolysis No O 2 O 2 Citric acid cycle and Electron transport chain Is split apart in

11. Alcoholic Fermentation Happens in microorganisms (yeast and bacteria) in the absence of oxygen (anaerobic) Alcohol and CO 2 are produced Does not produce ATP, but it does allow glycolysis to occur again and again Used in the beer and wine industry

12. Lactic Acid Fermentation Happens in muscle tissue of humans and other animals in the absence of oxygen (anaerobic) Lactic acid and CO 2 are produced Does not produce ATP, but it does allow glycolysis to occur again and again Produces burning feeling during exercise

13. When oxygen is present… Kreb’s cycle (citric acid cycle) and electron transport chain occur Both happen inside the mitochondria 2 ATP come from the Kreb’s cycle 32-34 ATP come from the electron transport chain Total of 36-38 ATP from cellular respiration (includes 2 ATP from glycolysis) * ATP amounts shown are produced from ONE glucose molecule

14. Aerobic vs. Anaerobic Aerobic Respiration Energy produced more slowly Oxygen needed Citric acid cycle and ETC More ATP are produced per molecule of glucose Anaerobic Respiration Energy produced quickly No oxygen needed Glycolysis and fermentation Few ATP produced

15. What is Photosynthesis? The process of using sunlight to convert CO 2 and water into glucose and oxygen CO 2 + H 2 OC 6 H 12 O 6 + O 2 Reaction takes place in the chloroplast

16. Converting Solar Energy Plants trap the sun’s energy using a green pigment called chlorophyll Chlorophyll is inside the chloroplast Solar energy is used to transform CO 2 into glucose

17. Factors that Affect Photosynthesis Water availability Light intensity (varies from species to species) Temperature (extremes slow down photosynthesis - below 0 o C and above 35 o C)

18. Photosynthesis is divided into two processes:

19. Overview of Light Dependent Reactions Require light to occur Produce oxygen gas Produce ATP

20. The Calvin Cycle Uses energy stored in ATP to produce glucose from CO 2. * Six CO 2 molecules from the atmosphere are needed to produce one glucose molecule

21. Summary of the Reactions of Photosynthesis

22. What is the glucose used for? Energy source for plant and consumers To build starches (stored food source) To build new cell walls

23. Cellular Respiration vs. Photosynthesis O 2 + carbohydrates (from photosynthesis) CO 2 (from cell respiration)