1. Breathing Is Only the Beginning
Cellular Respiration
Breathing Is Only the Beginning

2. Food Serves as source of materials for anabolic reactions in the body
Serves as source of energy
calorie: amount of energy needed to raise the temperature of 1 gram of water by 1-degree Celsius
Calorie: used on food labels; amount of energy needed to raise the temperature of 1000 grams (1kg) of water by 1-degree Celsius

3. Cellular Respiration-An Overview
Process that releases energy by breaking down glucose and other food molecules usually in the presence of oxygen

4. Cellular Respiration-An Overview
6O2 + C6H12O > 6CO2 + 6H2O + energy
Where in the cell is energy produced?
Mitochondria
What is the energy molecule in cells?
ATP

5. Cellular Respiration-An Overview
Three Stages
Glycolysis
Kreb’s Cycle
Electron Transport Chain

6. Glycolysis
The process of breaking one molecule of glucose (6C sugar) in half (2-3C sugars) to form pyruvic acid
Needs 2 ATP molecules to start this reaction
Forms 4 ATP molecules when completed

7. Glycolysis Releases 4 high energy electrons from glucose
Does NOT require oxygen to occur
Picked up by 2-NAD+ ions to form 2 NADH molecules that go to electron transport chain

8. Glycolysis

9. The Choice
If oxygen is present in the cells what follows glycolysis is the Krebs Cycle thru aerobic cellular respiration
If oxygen is not present in the cells what follows glycolysis is fermentation thru anaerobic cellular respiration

10. Kreb’s (citric acid) Cycle

11. Kreb’s (citric acid) Cycle
1-Pyruvic acid from glycolysis is broken down to carbon dioxide in a series of energy releasing reactions
Produces 3-CO2 released as waste
Produces 4-NADH and 1-FADH2 that goes to electron transport chain
Produces 1-ATP

13. Electron Transport Chain
Uses electrons from NADH (from glycolysis and Krebs Cycle) and FADH2 (from the Krebs Cycle) to make ATP from ADP

14. The Totals

15. The Totals

16. The Totals

17. The Totals

18. The Totals
1 molecule of glucose

19. Two Branches Fermentation
Process of producing energy from pyruvic acid without the presence of oxygen
Two Branches
Alcoholic
Lactic Acid

20. Alcoholic Fermentation
Used by yeast and some other microorganisms
Pyruvic acid + NADH ---- >
ethyl alcohol + carbon dioxide + NAD+

21. Lactic Acid Fermentation
Produces by muscle cells during rapid exercise
Produces burning sensation in muscles since it is a muscle paralyzer
Pyruvic acid + NADH ---- > lactic acid + NAD+

22. Lactic Acid Fermentation
Produces by microorganisms as a defense against predators
Pyruvic acid + NADH ---- > lactic acid + NAD+

23. Review Questions
What is the difference between a calorie and a Calorie?
Where does cellular respiration occur in the cell?
What are the two reactants in cellular respiration? What are the three products?
Name the three stages of cellular respiration.
What is the starting chemical in glycolysis? What are the two products of glycolysis?
Where do the electrons from the glucose molecules end up at the end of glycolysis?
What chemical determines if glycolysis is followed by aerobic or anaerobic respiration?
Why is breathing an important part of cellular respiration to animals?

24. Where does the pyruvic acid come from that starts the Kreb’s cycle?
What are the products of the Kreb’s cycle?
What are the products of the electron transport chain in cellular respiration?
How is aerobic cellular respiration different from anaerobic cellular respiration?
List at least two ways that alcoholic fermentation is different from lactic acid fermentation?
Why do both types of fermentation produce NAD+?
Where does the pyruvic acid come from that starts both types of fermentation?