1. Unit 2: Metabolic Processes
Unit Questions:
What is Energy? What is the biological definition of Energy?
What is the connection between photosynthesis and cellular respiration?
How do we obtain Energy from the food we eat?

3. Metabolic Processes in use!
DALIAN (2007) - Over 23 tonnes of oil-eating bacteria are being used to clean up the oil spill off the coast of northeast China's Dalian City, four days after pipelines exploded near one of China's largest oil reserve bases.

4. Thermodynamics and Metabolism
What is Energy? What is the biological definition of Energy?
Refresher: What are the Equations for Photosynthesis and Cellular Respiration???

5. Metabolism Metabolism: all chemical reactions occurring in an organism
Anabolism: chemical reactions that use energy to make new chemical bonds
Ex. ???
Catabolism: chemical reactions that release energy when bonds are broken

6. Metabolism Metabolism: all chemical reactions occurring in an organism
Anabolism: chemical reactions that use energy to make new chemical bonds
Ex. Photosynthesis is an anabolic reaction
Catabolism: chemical reactions that release energy when bonds are broken
Ex. Cellular Respiration is a catabolic reaction

7. Flow of Energy Energy: the capacity to do work
-kinetic energy: the energy of motion
-potential energy: stored energy
Energy can take many forms:
mechanical electric current
heat light

8. Think back to our biochemistry unit…
What is a redox reaction???

9. Think back to our biochemistry unit…
What is a redox reaction??? LEO the lion says GER!

10. Flow of Energy
Potential energy stored in chemical bonds can be transferred from one molecule to another through electrons.
oxidation: loss of electrons (LEO)
reduction: gain of electrons (GER)
redox reactions are coupled to each other.

13. Laws of Thermodynamics
First Law of Thermodynamics – energy cannot be created or destroyed
-energy can only be converted from one form to another
Example:
How does the process of photosynthesis demonstrate the first law of thermodynamics?

14. Laws of Thermodynamics
First Law of Thermodynamics – energy cannot be created or destroyed
-energy can only be converted from one form to another
Example:
sunlight energy chemical energy
photosynthesis

15. Laws of Thermodynamics
Second Law of Thermodynamics: disorder is more likely than order
entropy: disorder in the universe
The 2nd Law of Thermodynamics states that entropy is always increasing.

16. The messy bedroom law…

17. Laws of Thermodynamics: Gibb’s Free Energy
Free energy: the energy available to do work
-free energy symbol: G (Gibb’s free energy)
enthalpy: energy contained in a molecule’s chemical bonds

18. Laws of Thermodynamics
Chemical reactions can create changes in free energy.
When products contain more free energy than reactants DG is positive.
When reactants contain more free energy than products DG is negative.

19. Laws of Thermodynamics
Chemical reactions can be described by the transfer of energy that occurs:
endergonic reaction: a reaction requiring an input of energy
- DG is positive
exergonic reaction: a reaction that releases free energy
- DG is negative

21. Laws of Thermodynamics
Most reactions require some energy to get started.
activation energy: extra energy needed to get a reaction started
-destabilizes existing chemical bonds
-required even for exergonic reactions
catalysts: substances that lower the activation energy of a reaction
*What do we call a catalyst that speeds up biological reactions?

23. Energy Currency of Cells
ATP = adenosine triphosphate
-the energy “currency” of cells
ATP structure:
-ribose, a 5-carbon sugar
-adenine
-three phosphates

25. How do we use ATP ATP stores energy in the bonds between phosphates.
Phosphates are highly negative, therefore:
-the phosphates repel each other
-Lots of energy is required to keep the phosphates bound to each other
-Lots of energy is released when the bond between two phosphates is broken

26. Energy Currency of Cells
When the bond between phosphates is broken:
ATP ADP + Pi
energy is released
ADP = adenosine diphosphate
Pi = inorganic phosphate
This reaction is reversible.

27. Energy Currency of Cells
Is this an exergonic or endergonic reaction?
ATP ADP + Pi
energy is released

28. Energy Currency of Cells
Is this an exergonic or endergonic reaction?
ATP ADP + Pi
energy is released
EXERGONIC!

29. Energy Currency of Cells
Is this an Is this an anabolic or catabolic reaction??
ATP ADP + Pi
energy is released

30. Energy Currency of Cells
Is this an Is this an anabolic or catabolic reaction??
ATP ADP + Pi
energy is released
CATABOLIC! *Exergonic reactions that occur in living things are catabolic, endergonic reactions in living things are anabolic

32. Energy Currency of Cells
The energy released when ATP is broken down to ADP can be used to fuel endergonic reactions.
The energy released from an exergonic reaction can be used to fuel the production of ATP from ADP + Pi.