1. Cellular Respiration Energy For Cells

2. Energy Energy – capacity to perform work Kinetic energy – energy of motion Potential energy – stored energy Conservation of energy – energy cannot be created nor destroyed Energy is converted to heat Chemical energy – form of potential energy

3. Food Calories calorie – amount of energy that raises the temperature of 1 g of water by 1°C Kilocalorie – 1000 calories (these are the calories that appear on food labels)

4. ATP Energy is released by breaking the bonds of food molecules (such as glucose) to make ATP from ADP ATP = adenosine triphosphate ADP = adenosine diphosphate ADP + P i → ATP

5. ATP Cycle – energy coupling

6. Aerobic Respiration Respiration that requires oxygen Starts in the cytoplasm glycolysis Moves to the mitochondria Krebs Cycle Electron Transport Chain

7. Aerobic Respiration C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 38 ATP are produced per molecule of glucose 2 ATP are used, so net ATP is 36 Some energy is lost as heat, so the actual number will be lower Exergonic reaction – energy is released

8. Stage 1: Glycolysis “splitting of sugar” 6-C glucose broken down into two 3-C molecules (pyruvic acid)

9. Stage 2: The Krebs Cycle Named for Hans Krebs (1930s) Pyruvic acid must first be converted to aceytl-CoA (acetic acid – 2-C compound – bonded to coenzyme A) Acetic acid molecules then broken all the way down to CO 2 Produces ATP and NADH & FADH 2, which will be converted to ATP later

10. Stage 2: The Krebs Cycle cont.

11. Stage 3: Electron Transport Chain Inner membrane of mitochondria H+ are pumped to the outside of the membrane creating potential energy ATP synthase uses energy from the movement of the H+ back inside to attach phosphate groups to ADP to make ATP

12. Stage 3: Electron Transport Chain

13. Anaerobic Respiration Takes place in the absence of oxygen Fewer ATP are produced – net ATP is 2 2 types Lactic acid fermentation Alcoholic fermentation

14. Lactic Acid Fermentation Enzymes break down a glucose molecule into two lactic acid molecules, transferring energy to ATP C 6 H 12 O 6 + 4ADP + 4P i  lactic acid + 4ATP Heavy breathing after activity needed to replenish oxygen

15. Lactic Acid Fermentation

16. Alcoholic Fermentation Enzymes break down a glucose molecule into two molecules of ethyl alcohol and two molecules of CO 2, transferring energy to ATP C 6 H 12 O 6 + 4ADP + 4P i  2 ethanol + 2CO 2 + 4ATP This process is used… to produce alcohol in gasoline additives baking

17. Alcoholic Fermentation

18. Anaerobes vs. Aerobes Facultative anaerobe – organism (such as yeast) that can obtain energy b either respiration or fermentation Obligate anaerobes – organisms that are poisoned by oxygen (cannot perform respiration) Obligate aerobes – need oxygen and cellular respiration to live

19. Photosynthesis vs. Respiration