1. Converting Energy Chapter 5
Part 1:
Cellular Respiration

2. Prior Knowledge Metabolism (p.7) Glucose (p.34)
Energy and Chemical Reactions (p.38)
Enzymes (p. 40 & 41)
Mitochondria (p.65)
Chloroplast (p.66)
Energy flow in Ecosystems (p )
Water and Carbon Cycles (p )
Autotroph & Heterotrophs

3. Energy and Living Things
Energy is the ability to move or change matter
(light, heat, chemical, electrical, etc.)
Energy can be stored or released by chemical reactions.
Energy from the sunlight flows through living systems, from autotrophs to heterotrophs.
Cellular respiration and photosynthesis form a cycle because one process uses the products of the other.
ATP supplies cells with energy needed for metabolism.

4. ATP (adenosine triphosphate)
Cells need a steady supply of ATP to function
ATP is produced through the process of cellular respiration
produced in the mitochondria

5. ATP
It is a nucleotide (nitrogen containing base: adenine, a 5 carbon sugar:ribose, phosphate group) with two extra energy-storing phosphate groups

6. ATP
The phosphate groups store energy like a compressed spring does. This energy is released when the bonds that hold the phosphate groups together are broken.
The removal of a phosphate group from ATP produces adenosine diphosphate, or ADP. This reaction releases energy in a way that enables the cell to use energy.
Cells use the energy released by this reaction to power metabolism.

7. Tour de France: How do they do it? 5,900 - 9,000 :
Calories consumed by a rider per day
2,241 miles:
the total distance
42,000:
water bottles used by teams in race
3: number of weeks the tour lasts

8. Major Parts of the Machine
Based on: Starr, C. Biology: Concepts and Applications, Brooks/Cole
food, water intake
oxygen intake
elimination of carbon dioxide
Digestive System
Respiratory System
Absorption
nutrients,
water,
salts
oxygen
carbon
dioxide
Circulatory System
elimination
of food
residues
rapid transport
to and from all
living cells

9. Systems involved: Digestive system – nutrient absorption from food
Circulatory system – gas exchange
Respiratory system – gas exchange

10. Cellular Respiration :
*Process by which cells produce energy (ATP) from breaking down glucose
*Reactants: oxygen & glucose
*Products: carbon dioxide, water, ATP
Enzymes are specialized proteins that catalyse, affect the rate, of metabolic processes
Cellular Respiration Equation:
enzymes
C6H12O O2  6CO H2O + ATP
glucose oxygen  carbon dioxide + water + ATP (energy)

11. Stage 1: Glycolysis Can take place with or without oxygen
Converts glucose to 2 molecules of pyruvic acid
Uses 2 ATP molecules but produces 4 ATP molecules = net gain of 2ATP molecules
Occurs in cytoplasm of cell on mitochondrial outer membrane

12. Cellular Respiration Stage 1:Gycolysis
glucose
2 ATP
2 pyruvic acid
Oxygen Independent
(can take place with without O2)

13. Stage 2: Oxygen Required
Production of ATP
Kreb’s Cycle
Aerobic reaction oxygen must be present to start cycle
2 pyruvic acids enter mitochondria
Pyruvic acid binds with acetyl-CoA
Produces CO2 as a waste product

14. Stage 2: Production of ATP
Oxygen required
The Electron Transport Chain
Aerobic
Inner membrane of the mitochondria

15. Cellular Respiration Stage 2: With Oxygen
pyruvic acid
+O CO2
Krebs cycle, H2O
electron transport chain
(in mitochondria) ATP (energy)
molecules formed

16. Total ATP production from one molecule of glucose
Result of Aerobic Respiration
Process
Net ATP
Glycolysis 2
Kreb’s Cycle 36
Electron Transport Chain
Total ATP production from one molecule of glucose 38

17. Fermentation: Respiration in the absence of Oxygen
Breakdown of carbohydrates in the absence of oxygen
When there is no O2 available for Kreb’s cycle, cells undergo fermentation
Anaerobic process (no oxygen used)
ATP is still produced until oxygen returns to cells

18. Cellular respiration Stage 2: No oxygen present
pyruvic acid
CO2
alcohol (in yeasts or some bacteria)
or lactic acid

19. Types of Fermentation:
Lactic acid fermentation – produces lactic acid as byproduct
Lactic acid fermentation by some prokaryotes and fungi is used in the production of foods – cheese and yogurt
Alcoholic fermentation – produces ethanol
Carbon dioxide released by yeast causes the rising of bread dough and the carbonation of some alcoholic beverages.

20. More on lactic acid
Some cells such as muscle cells revert to fermentation when oxygen is in short supply (exercise). Blood cannot supply O2 fast enough, therefore, they produce ATP without using O2. The product is lactic acid. In high concentrations, lactic acid causes fatigue & muscle failure (sore muscles). Muscle cells will return to normal when O2 is supplied to chemically change lactic acid.
There is current research that says that muscle soreness could be more related to actually tears in the muscle tissues and that lactic acid quickly leaves the muscles.

21. Comparing Anaerobic vs. Aerobic
Lactic Acid Fermentation
Alcoholic Fermentation
Aerobic Respiration
Glucose
Glycolysis
Lactic acid and 2 ATP
Carbon dioxide, ethanol, 2 ATP
Carbon dioxide, water, and 38 ATP
Production of ATP is more efficient in the presence of oxygen!

22. Electron Transport Chain
Glucose making 2 molecules of pyruvic acid in an anaerobic environment
Stage 1
GLYCOLYSIS
Pyruvic acid is converted to carbon dioxide and water and 36 molecules of ATP are produced
Stage 2: O2 present
KREB’S CYCLE
(CITRIC ACID CYCLE)
Electron Transport Chain
Pyruvic acid is converted to carbon dioxide and either alcohol or lactic acid
Stage 2: No O2 present
Fermentation

23. It is taken to the lungs and exhaled out of the body
What happens to the excess CO2 produced in the cell as a waste product of respiration?
C6H12O O2  6CO H2O + ATP
It is taken to the lungs and exhaled out of the body

24. What would happen to a cell if it had no mitochondria?
It would not be able to produce energy and would die.