2. 2009-2010 Cellular Respiration Harvesting Chemical Energy ATP

3. Energy needs of life Animals are energy _________ (consumer/producer) – What do we need energy for? synthesis (building for growth) reproduction active transport movement temperature control (making heat)

4. ATP What is energy in biology? Adenosine Tri-Phosphate

5. How Do We Get Energy From ATP? By breaking the high- energy bonds between the last two phosphates in ATP By breaking the high- energy bonds between the last two phosphates in ATP

6. Harvesting energy stored in food Cellular respiration: a set of metabolic reactions and processes that take place in the cells of organisms to convert food into ATP There are two types of cellular respiration: 1.Aerobic respiration: Requires oxygen 2.Anaerobic respiration: Do not require oxygen Aerobic respiration is the most common one

7. Aerobic Respiration Requires Oxygen There are 3 stages in aerobic respiration: 1.Glycolysis 2.The Krebs Cycle 3.Electron Transport Chain It generates total 36 ATP The equation of aerobic respiration is as follow: C 6 H 12 O 6 __O 2 ATP __CO 2 __H 2 O  + ++ glucose + oxygen  energy + carbon + water dioxide

8. Diagram of the Process Occurs in Cytoplasm Occurs in Matrix Occurs across Cristae

9. Glycolysis The first step of aerobic respiration It takes place in cytoplasm This pathway does not require oxygen The process coverts one molecule of glucose into two molecules of pyruvate (pyruvic acid) It also generates: -2 net ATP : 4 molecules of ATP per glucose are produced, but 2 are consumed in the process

10. Krebs Cycle It is also called Citric Acid Cycle It takes place in the matrix of the mitochondria

11. Krebs Cycle It requires Oxygen The Krebs Cycle turns twice per glucose molecule Each turn of the Krebs Cycle also produces: -2 CO 2 -1 ATP Therefore, for each glucose molecule, the Krebs Cycle produces: -4 CO 2 -2 ATP

12. Electron Transport Chain It requires Oxygen It takes place in the Cristae of the Mitochondrion

13. Electron Transport Chain Through a series of reactions, the “high energy” electrons are passed to oxygen In the process, a proton (H+) gradient is formed, and 32 ATP is produced per glucose Water is also created

14. ATP Counting Glycolysis: 2 ATP Krebs Cycle: 2 ATP Electron Transport Chain: 32 ATP Total: 36 ATP

15. Anaerobic Respiration Also known as fermentation There are 2 types of fermentation - alcohol fermentation -lactic acid fermentation Fermentation happens when: - no oxygen - no mitochondria (bacteria) Can only make very little ATP - Only 2 ATP per glucose - large animals cannot survive on anaerobic respiration Requires NADH to produce ATP

16. Anaerobic Respiration Fermentation – alcohol fermentation Yeast – glucose  ATP + CO 2 + alcohol – make beer, wine, bread – lactic acid fermentation E.g. bacteria, animals – glucose  ATP + lactic acid – bacteria make yogurt – animals feel muscle fatigue