1. Cellular Respiration
ATP

2. Cellular respiration overview (3:50)
Cell Respiration Preview (6:40)

3. Chemical Energy and Food
A lot of energy in food- one gram of glucose has 3811 calories
A calorie is the amount of energy it takes to raise 1 gram of water 1 degree Celsius
A food calorie (also called a Kilocalorie-kcal) is equal to 1000 “chemistry” calories

4. Chemical Energy and food cont…
Cells do not burn glucose- they gradually release energy from glucose (food).
The process of breaking down glucose is called cellular respiration.

5. Cellular Respiration 6O2 +C6H12O6 6CO2 + 6H2O + energy
Look familiar? It’s photosynthesis but backwards!
Cellular Respiration-
Breaking down food
in the presence of
OXYGEN.

6. Cellular Respiration cont
Cellular respiration is made of 3 parts:
1. Begins with glycolysis (takes place in the cytoplasm)
2. Krebs Cycle (mitochondria)
3. Electron Transport Chain (mitochondria)

7. Cellular Respiration Summary

8. To the electron transport chain
Glycolysis
Glycolysis is the process in which one molecule of glucose (6 carbons) is broken in half producing two molecules of pyruvic acid (3 carbons each)
Occurs in cytoplasm of cell
Even though glycolysis is part of an energy releasing process, it takes some energy to get it started.
2 ATP used, 4 ATP produced = 2 net ATP produced
NADH produced (high energy electron carrier)
Glucose
To the electron transport chain
2 Pyruvic acid
2 ATP are used and then 4 ATP are produced.

9. Fermentation (without oxygen)
Krebs Cycle
After Glycolysis, if there is oxygen present then another path is taken, one that is aerobic
Glucose
Glycolysis
Krebs cycle
Electron transport
Fermentation (without oxygen)
Alcohol or lactic acid

10. Krebs Cycle cont…
The second stage of cellular respiration is the Krebs Cycle
During the Krebs cycle, Pyruvic acid is broken down into carbon dioxide
Pyruvic acid CO2
Also known as the “citric acid cycle”

11. Citric Acid Production
The Krebs Cycle cont…
Section 9-2
Citric Acid Production
Mitochondrion
Besides CO2, what else is produced?
1 ATP produced: used for cellular activities
NADH/FADH2 (high energy electron carriers) produced: go to electron transport chain

12. Electron Transport Chain
The electron transport chain uses electrons from the Krebs cycle to convert ADP ATP

13. Electron Transport Chain
Section 9-2
Inner
Membrane
Matrix
Intermembrane
Space
Electron Transport
Hydrogen Ion Movement
ATP Production
ATP synthase
Channel
Mitochondrion
H+ concentration gradient is built up
H+ ions diffuse through ATP synthase protein
As ATP synthase spins, it creates ATP
At the end of the chain, electron is combined with H and O to produce water (H2O)

15. Energy and Exercise
In order for a human body to move it needs ATP for energy
In the beginning of exercise, the body uses stored ATP in cells (but only for a few seconds of energy)
Then the body relies on ATP made from lactic acid (for about seconds)

16. Energy and Exercise cont…
For long term, the body needs to use cellular respiration as source of ATP
This supply of ATP is continuous but not instantaneous
Body has enough stores of glycogen (sugars) to supply cellular respiration for minutes
After minutes, must break down other molecules, fats, to use for energy

17. A video demonstrating the importance of oxygen in exercise…

18. Fermentation (without oxygen)
Chemical Pathways
Glucose
Glycolysis
Krebs cycle
Electron transport
Fermentation (without oxygen)
Alcohol or lactic acid

19. Fermentation
When oxygen is not present, glycolysis is followed by fermentation
Fermentation is anaerobic (doesn’t need oxygen)
There are two types:
Alcoholic fermentation
Lactic acid fermentation

20. Fermentation cont..

21. Alcoholic Fermentation
Used by yeast and other micro organisms forming alcohol and CO2 as wastes
Pyruvic acids + NADH  alcohol + CO2 + NAD+

22. Lactic Acid Fermentation
Lactic Acid forms in muscles when the body cannot supply enough oxygen to its tissues
When you exercise very quickly your muscles run out of oxygen, and your body begins to produce ATP by lactic acid production

23. Energy Movie- click to play