1. CHAPTER 9: CELLULAR RESPIRATION
Lab Biology CP

2. Chapter 9: Cellular Respiration
9.1 Cellular Respiration: An Overview
9.2 The Process of Cellular Respiration
9.3 Fermentation

3. 9.1 & 9.2 Cellular Respiration

4. Chemical Energy and Food
Food provides living things with the chemical building blocks they need to grow and reproduce.
Food molecules contain energy that is released when its chemical bonds are broken.
Energy stored in food is expressed in units of calories.
Cells use all sorts of molecules for food, including fats, proteins, and carbohydrates.
Cells break down food to produce ATP.

5. Overview of Cellular Respiration
Chemical equation for Cellular Respiration:
6 O2 + C6H12O6  6 CO2 + 6 H2O + Energy
Write the chemical equation for Photosynthesis:
* Explain how this chemical equation compares to the equation for photosynthesis. ____________________________________________________________________________________________________________________________________

6. Stages of Cellular Respiration
1. Glycolysis
2. Krebs Cycle
3. Electron Transport Chain

7. ATP Production and Cellular Respiration
Glycolysis
Makes only a small amount of ATP/energy
Krebs Cycle
makes a little more energy/ATP from pyruvic acid.
Electron Transport Chain produces the bulk of the energy/ATP

8. Glycolysis- happens 1st (without oxygen).
Is an anaerobic process. It can take place without oxygen being present in the cell.
Makes 2 ATP
It takes place in the cytoplasm of a cell.

9. Krebs Cycle- happens 2nd (with oxygen)
Is aerobic. It only happens when there is oxygen present in the cell.
Takes place inside the mitochondria.

10. Electron Transport Chain- happens 3rd (with oxygen)
Is aerobic. It only happens when there is oxygen present in the cell.
Takes place inside the mitochondria.

11. Total ATP Production during Cellular Respiration
Together glycolysis, the Krebs's cycle, and the electron transport chain release 36 molecules of ATP per molecule of glucose.

12. Comparing Photosynthesis and Cellular Respiration
Photosynthesis and cellular respiration are opposite processes.
The energy flows in opposite directions. Photosynthesis “deposits” energy, and cellular respiration “withdraws” energy.
The reactants of cellular respiration are the products of photosynthesis and vice versa.

13. 9.3 Fermentation

14. Fermentation
Fermentation is a process by which energy can be released from food molecules in the absence of oxygen. Fermentation occurs in the cytoplasm of cells.

15. Fermentation
Under anaerobic conditions, fermentation follows glycolysis.

16. Alcoholic Fermentation
Yeast and a few other microorganisms use alcoholic fermentation that produces ethyl alcohol and carbon dioxide.
This process is used to produce alcoholic beverages and causes bread dough to rise.

17. Alcoholic Fermentation
Chemical equation:
Pyruvic acid + NADH  Alcohol + CO2 + NAD+

18. Lactic Acid Fermentation
Most organisms, including humans, carry out fermentation using a chemical reaction that converts pyruvic acid to lactic acid.
Chemical equation:
Pyruvic acid + NADH  Lactic acid + NAD+

19. Quick Energy
Cells normally contain small amounts of ATP produced during cellular respiration, enough for a few seconds of intense activity.
Lactic acid fermentation can supply enough ATP to last about 90 seconds. However, extra oxygen is required to get rid of the lactic acid produced. Following intense exercise, a person will huff and puff for several minutes in order to pay back the built-up “oxygen debt” and clear the lactic acid from the body.

20. Long-Term Energy
For intense exercise lasting longer than 90 seconds, cellular respiration is required to continue production of ATP.
Cellular respiration releases energy more slowly than fermentation does.
The body stores energy in the form of the carbohydrate glycogen. These glycogen stores are enough to last for 15 to 20 minutes of activity. After that, the body begins to break down other stored molecules, including fats, for energy.