1. Energy in a Cell Cellular Respiration

2. Cellular respiration: process where mitochondria break down food molecules to produce ATP. (energy)

3. Cellular Respiration Three stages in cellular respiration: glycolysis, citric acid cycle, and electron transport chain.

4. Cellular Respiration Mitochondria is called the powerhouse of the cell because it is the site of cellular respiration.

5. Cellular Respiration More work a cell does, the more mitochondria it has.

7. Cellular Respiration Glycolysis: first stage of cellular respiration.

8. Cellular Respiration Takes place in the cytoplasm of the cell.

9. Cellular Respiration One C 6 H 12 O 6 (glucose) is broken down into 2 pyruvic acid molecules. (a 3 C molecule)

10. Cellular Respiration For every glucose molecule broken down, 2 ATP molecules are produced.

11. Cellular Respiration Next, the pyruvic acid moves into the mitochondria.

12. Cellular Respiration Citric acid cycle or Kreb’s cycle : Pyruvic acid is broken down in a series of reactions to produce 2 CO 2 and 1 ATP and electrons are passed on to the electron transport chain.

13. Cellular Respiration Electron transport chain: series of proteins where electrons are passed.

14. Cellular Respiration Energy is released as electrons are passed from one molecule to the next.

15. Cellular Respiration The released energy is used to make ATP.

16. Overall: For every glucose that enters cellular respiration 36 ATP are produced.

17. Cellular Respiration Cellular respiration can be classified as aerobic: cellular respiration occurs in the presence of O 2.

18. Cellular Respiration Most efficient form of respiration.

19. Cellular Respiration Krebs cycle is aerobic respiration.

20. Cellular Respiration Cellular respiration can also be classified as anaerobic: respiration that proceeds in the absence of O 2.

21. Cellular Respiration Glycolysis is anaerobic respiration.

22. Cellular Respiration Not as efficient as aerobic. Only 2 ATP formed.

23. Cellular Respiration In the absence of O 2, pyruvic acid backs up and is eliminated 2 ways:

24. Cellular Respiration 1.In you and me, pyruvic acid is converted to lactic acid and builds up in the muscles.

25. Cellular Respiration 2.In yeast, pyruvic acid converted to CO 2 and ethyl alcohol. This makes bread rise.

26. Cellular Respiration Anaerobic respiration is also called fermentation.

27. Cellular Respiration Which molecule has the most stored energy: fat or carbohydrate?

28. Cellular Respiration Fat – it has available energy for 51 ATP.