1. UNIT 3 Cell Processes: ATP, Cellular Respiration, Photosynthesis

2. What is ATP?
Adenosine triphosphate (ATP) is the usable form of energy produced by respiration.
Respiration: transporting oxygen and carbon dioxide between cells and the external environment

3. Cells need energy for… Movement Metabolism Homeostasis
Active Transport
Bioluminescence
Muscle cells
Heart muscle cells
Brain cells

4. How do organisms get their energy???
Autotrophs
Also called producers
Use energy from the sun or chemicals to make organic food molecules (carbohydrates – glucose!)
Plants!
Heterotrophs
Also called consumers
Eat other organisms
US!

5. Energy flow
Energy flows from autotrophs to heterotrophs, and from prey to predator

7. ATP as energy currency
Cells can’t use all of their organic molecules energy at once.
Energy is transferred from organic molecules to be stored in adenosine tri- phosphate (ATP).
The energy in ATP is released and used as needed.

8. ATP - Importance
It's the main molecule supplying the energy that cells need to carry out their day-to-day business.
It takes the chemical energy from our food and makes it available for useful work.

9. ATP Adenosine triphosphate contains stored energy.
A single molecule of ATP contains ten carbon atoms, sixteen hydrogen, five nitrogen, thirteen oxygen and three phosphorus atoms.
The shorthand formula is C10H16N5O13P3

10. Chemical Structure of ATP
Adenine Base
3 Phosphates
Ribose Sugar

11. What Does ATP Do for You?
It supplies YOU with ENERGY!

12. How Do We Get Energy From ATP?
By breaking the high- energy bonds between the last two phosphates in ATP

13. MAKING ATP
ATP is formed by ADP (adenosine and two phosphates) bonding with another phosphate. This bond stores the energy.
When the bond is broken the energy is released to be used by the cell
ADP can be reused to store more energy and released when required

14. How Does That Happen?
An Enzyme!
ATPase

15. How is ATP Re-Made? The reverse of the previous process occurs.
Another Enzyme is used!
ATP Synthase

16. The ADP-ATP Cycle
ATP Synthase
ATP-ase

17. When is ATP Made in the Body?
During a Process called Cellular Respiration

18. Cellular Respiration is the process that releases energy by breaking down food molecules in the presence of oxygen.
6O2 + C6H12O6  6CO2 + 6H2O + Energy
Oxygen + Glucose  Carbon Dioxide + Water + Energy

19. Cellular Respiration Requires oxygen
Glucose is oxidized and O2 is reduced
Glucose breakdown is an oxidation-reduction reaction
Breakdown of one glucose results in up to 38 ATP molecules

20. Overall Equation for Cellular Respiration
C6H12O O2
YIELDS
6CO2 + 6H20 + e ATP’s

21. What are the Stages of Cellular Respiration?
Glycolysis
The Krebs Cycle
The Electron Transport Chain

22. Where Does Cellular Respiration Take Place?
It actually takes place in two parts of the cell:
Glycolysis occurs in the Cytoplasm
Krebs Cycle & ETC Take place in the Mitochondria

23. Mitochondria Structure
Smooth outer Membrane
Folded inner membrane
Folds called Cristae
Space inside cristae called the Matrix

24. Making ATP
Two processes that can occur depending on if oxygen is present or not.
Aerobic respiration needs oxygen
1 molecule of glucose has the ability to convert 38 molecules of ADP to ATP (storing lots of energy). It completely breaks down glucose.
Anaerobic respiration does not require oxygen and makes only 2 ATP molecules

25. Glycolysis Requires input of 2 ATP Takes place in the Cytoplasm
Anaerobic = Doesn’t Use Oxygen
Requires input of 2 ATP
Glucose split into two molecules of Pyruvate or Pyruvic Acid

27. Fermentation Doesn’t require oxygen (anaerobic)
1. Lactic Acid fermentation in muscle cells (makes muscles tired)
2. Alcoholic fermentation in yeast (produces ethanol)
Nets only 2 ATP

28. Krebs Cycle History Discovered by Hans Krebs in 1937
He received the Nobel Prize in physiology or medicine in 1953 for his discovery
Forced to leave Germany prior to WWII because he was Jewish

29. Krebs Cycle Summary
During the Krebs Cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.
Citric Acid is created in this cycle thus giving it the nickname Citric Acid cycle.
Net ATP Production is 2 ATP.
Takes place in matrix of mitochondria

30. Electron Transport Chain Summary
The electron transport chain uses the high-energy electrons from the Krebs Cycle to convert ADP to ATP.
Total ATP 34.
Occurs Across Inner Mitochondrial membrane

31. Totals Gycolysis 2 ATP Krebs Cycle 2 ATP
Electron Transport Chain ATP
Total = ATP

32. ATP-ADP cycle – two types of energy
Potential Energy is stored energy that is currently not in use, but it is available and can be released at a later point. Chemical bonds contain potential energy because when they are broken their energy stored within them is released.
Kinetic Energy is also called free energy. This is energy that is being used now and it is doing work.

33. Aerobic/Anaerobic Anaerobic Aerobic Glycolysis in cytoplasm
No oxygen
2 ATP molecules
Animals: Lactic acid
Plants: Ethanol and Carbon Dioxide
Aerobic
Glycolysis in cytoplasm
With oxygen - mitochondria
Produces up to 38ATP molecules

34. A Crash Course video with our friend Hank

35. Comparing Photosynthesis & Respiration
Cellular Respiration
Function
Energy Storage
Energy Release
Location
Chloroplasts
Mitochondria
Reactants
CO2 and H2O
C6H12O6 and O2
Products
Equation
6CO2 + 6H2O  C6H12O6 + 6O2
C6H12O6 + 6O2
6CO2 + 6H2O

36. And now an entertaining youtube video!

37. Discussion Questions What do organisms need energy for?
Explain the difference between an autotroph and a heterotroph.
Which organisms are on the bottom of a food web?
Which direction does energy flow in a food web?

38. Discussion questions Who has the most energy available in a food web?
In a food web, what is the ultimate source of energy?
What is ATP?
How is ATP formed?