1. 9.1 Cellular Respiration

2. Feel the Burn
Do you like to bike, run, or swim? These are good ways to exercise. When you exercise, your body uses O2 to get energy from glucose, a 6-carbon sugar.
1. How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 min. into the run? 10 min. into the run?
2. What do you think is happening in your cells to cause the changes in how you feel?
3. Think about running as fast as you can for a 100 meter run. Could you keep this pace for a long distance? Explain.

3. Chemical Energy and Food
1 gram of glucose releases 3811 calories.
A calorie-amount of heat energy required to raise the temperature of 1 gram of water 1 degree Celsius.
A Calorie-Kilocalorie=1000 calories
(food labels)

4. Overview of Cellular Respiration
Glycolysis, the Krebs cycle, and the electron transport chain make up a process called CELLULAR RESPIRATION
Cellular Respiration is a process that releases energy by breaking down food molecules in the presence of oxygen.

5. Equation for Cellular Respiration
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
Remind you of anything???

6. Cellular Respiration Requires oxygen (aerobic)
Breaks down food to release energy
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
So what is the food that is being broken down???

7. Cellular Respiration Takes place in the mitochondria.
1st reaction takes place in the inner membrane
2nd reaction in the inner-inner membrane (the cristae or coiled inner membrane)
Makes 34 ATPs

8. FIRST STEP The first step of cellular respiration is glycolysis.
Glycolysis-produces 2 molecules of pyruvic acid, 2 molecules of ATP, and 2 molecules of NADH.

9. Glycolysis Breaks down glucose Does NOT require oxygen (anaerobic)
Takes place in the cytoplasm
6-carbon sugar is split into a 3 carbon PGAL molecule. (2 ATP’s are used here)
4 molecules of ADP are built up to ATP
-2 ATP(start)+4 ATP(made)=2 ATP net total

10. Glycolysis pathways
At the end of glycolysis about 90% of the chemical NRG in glucose was not used.
Cells get that energy by using OXYGEN.
If oxygen IS present…glycolysis will go into cellular respiration.

11. 9.2 The Krebs Cycle and Electron Transport
1. Krebs Cycle -1st step in respiration (inner membrane of mitochondria) breaks down carbs, proteins, and lipids.
2. Electron Transport- H+ and O-2 form H2O. ADP to ATP.
3. ATP Formation -different charges release NRG in the form of ATP.

12. In Summary Glycolysis has two choices:
If O2 is present glycolysis will go into cellular respiration to supply body with oxygen and ATP
If O2 is NOT present then glycolysis will go into the fermentation process.

13. The TOTALS of ATP
Glycolysis 2 ATP
Respiration 34 ATP
36 ATP

14. This is what happens…
Cellular respiration will pick up the pace and continue the supply of ATP.
Muscles and other body parts store NRG (last min.) after that your body burns stored molecules…FATS.
Body uses NRG to release heat when we exercise. Conserves heat in winter to stay warm.

15. Fermentation
An anaerobic process (doesn’t require oxygen)

16. Alcoholic Fermentation
Pyruvic Acid is broken down to produce 2 carbon alcohol and CO2
Bakers and brewers
Dough to rise (air spaces in bread)
CO2 released by fermentation=bubbles in beers or wine
When alcohol reaches 12%, yeast cells die.

17. Alcolholic Fermentation

18. Lactic Acid Fermentation
Pyruvic Acid accumulates as a result of glycolysis converted to lactic acid
Lactic acid produced in muscles during rapid exercise when body cannot supply enough O2 to the tissue to produce all ATP required
Burning, painful a few sec. after exercise
Large muscles cannot get enough oxygen

19. Lactic Acid Fermentation
What to do to help???
Stretch
Drink lots of water
Don’t forget to breathe!

20. Exercise and Energy Anaerobic (glycolysis) only last a short period.
Once runner is at 50 meter mark almost all ATP is gone~90 sec.
Fermentation builds up (lactic acid) need to replenish body with breathing.
What if race is longer than 90 sec.?

21. Homework Cellular respiration Aerobic Glycolysis Anaerobic
Design your own concept map of Chapter 9. Use the following terms in your concept map.
Cellular respiration
Aerobic
Glycolysis
Anaerobic
Fermentation
Pyruvic acid
Lactic Acid Fermentation
Alcoholic Fermentation
Mitochondria
Kreb Cycle
ATP
Glucose
Calorie
Exercise