1. Cellular Energy Production
Plant, Bacteria, & Animal Cells

2. Cellular Comparison: Plants, Animals, Bacteria

3. Plant Cells & Photosynthesis
Process of plants where sunlight energy, water, and carbon dioxide (CO2) create glucose & O2
Contrast with Cellular Respiration (what animal cells do in the mitochondria) where glucose is broken down and oxygen is used as a catalyst to produce energy molecules with water and CO2 as byproducts
Chlorophyll in the chloroplasts absorbs red and blue light, but reflects green light—this is why plants appear as green to us

4. Plant Cells & Photosynthesis
Two Stages
Light Dependent Reactions per handout
Light Independent Reactions per handout
Chemical Reaction of Photosynthesis:
6CO2 + Sunlight Energy + 6H2O >
C6H12O6 (glucose) + 6O2

5. Fermentation: Energy Creation Without Oxygen
Completed by many levels of organisms: anaerobic bacteria, animal muscle cells, some protozoa
Oxygen is not involved in the process, but may be present in some molecules
Fermentation happens in animals when the body is depleted of oxygen, but still needs energy for basic body functions: i.e. heart, lungs, brain

6. Fermentation: 2 parts Part 1: Glycolysis
Takes place outside the mitochondria in the cell cytoplasm, most likely by lysosomes
Forms 2 molecules of pyruvic acid and 2 molecules of ATP, the molecule of energy

7. Part 2: Fermentation Action 2 types depending on Organism
Alcohol Ferment:
Yeasts do this in production of liquor and bread
Reaction:
Glucose broken down into pyruvic acid which is converted to alcohol, carbon dioxide and ATP
(See handout for actual reaction formula)
Lactic Acid Ferment:
Used in production of cheese, milk, yogurt,
Product of many bacterial processes
Occurs in muscle cells when body is oxygen depleted; results in cramps
Reaction: Glucose broken down into pyruvic acid, which is converted to lactic acid and ATP
Lactic acid is processed in liver and converted back to glucose and used as energy (see handout)

8. Fermentation vs. Cellular Respiration
In Fermentation, one glucose molecule is used to create 4 total ATP molecules, but 2 ATP are used to break down glucose, so the net gain is just 2 ATP molecules
In Cellular Respiration (with oxygen), one glucose molecule is used to create 40 total ATP molecules, but 2 ATP are used to break down glucose, so the net gain is 38 ATP molecules
Obviously, Cellular Respiration is much more efficient for production of ATP energy

9. Cellular Respiration
Completed in several stages in several locations within the cell:
within the cytoplasm of the cell,
within the spaces of the mitochondria
across the walls of the mitochondria

10. Cellular Respiration: Part 1: Glycolysis
Takes place in cytoplasm of cell, most likely within the lysosomes
Energy required in this step—2 ATP molecules for each glucose molecule
This diagram is more detailed than needed for our study, but provides a good summation of the complexity of the process

11. Cellular Respiration: Glycolysis continued
ADP molecules are reused to produce ATP energy molecules
From original single molecule of glucose; 4 ATP energy molecules produced (2 ATP used); net gain 2 ATP molecules
Final products:
2 ATP net molecules
2 Pyruvate molecules

12. Cellular Respiration: Part 2: Prep for Krebs Cycle
Takes place in inner compartment of mitochondria—not across the folds, but between the folds of the mitochondria
Each pyruvate molecule is converted to a molecule called acetyl-CoA with the other products: 1 molecule of carbon dioxide and 1 NADH molecule (again, don’t get bogged down with the abbreviations of NAD, NADH, etc)

13. Cellular Respiration: Part 2—Krebs Cycle
Takes place between folds of mitochondria
Each acetyl-CoA molecule goes through many changes with water infused, many molecules converted, carbon dioxide released
Final product is one molecule of ATP per each molecule of acetyl-CoA converted

14. Cellular Respiration: Part 3 Electron Transport Chain
The final step of Cellular respiration takes place throughout and across the walls of the mitochondria
This step utilizes the electrons that have been freed during the several previous steps of cell respiration
These electrons are used to drive the final oxidation rxn (use of oxygen molecules) that drives the sodium-potassium pump across the mitochondrion walls
Final products of the electron transport chain are an additional 34 molecules of ATP energy

15. Final Totals of ATP Produced per each molecule of Glucose
Cellular Respiration
Final Totals of ATP Produced per each molecule of Glucose
Cycle ATP produced ATP used
Glycolysis
Krebs Cycle
Electron Chain ________________
Totals minus 2 used
equals net gain of 38 ATP molecules

16. Cellular Respiration: Overall diagram of Process

17. Energy Pathways in Animal Cells
See p. 301
Animals use Carbos, Fats, or Proteins as their main source of energy.
All nutrients enter the Cellular Resp. process at different stages, but all used in Mitochondria within cells.