1. Energy Energy—The ability to do work.
There are essentially two types of energy associated with electrons and chemical bonds – Potential and Kinetic.
To make the four macromolecules of life requires energy and dehydration synthesis reactions. To be break them apart releases energy and requires hydrolysis.

2. Metabolism
The sum of all the chemical reactions occurring in an organism.
The collective process has two separate phases.
Catabolism – This refers to the breaking down (hydrolysis) of a molecule.
This process releases “potential” E found in the chemical bond between monomers.
This is an exergonic reaction because it releases heat to the environment.
Think Catastrophe; breaking up things. Like digestion in your body.
Anabolism –This is the assembly (synthesis) of molecules.
This process requires “Kinetic” E to position molecules in away so as to create a chemical bond between monomers.
This is an endergonic reaction because it absorbs energy from the environment.
Think Anabolic steroids; these BUILD muscle.
This is a great example of Energy Coupling – two different processes united by common energy

3. Energy Adenosine Triphosphate ATP Structure Uses
Instantly Accessible Energy
“Energy Currency of the Cell”
Store only enough to sustain the body for 20 seconds.
Hydrolysis of ATP
ATP + Water--->ADP + P+ Energy
occurs spontaneously
exergonic
Endergonic

4. Energy Exergonic Reactions Endergonic Reactions Spontaneous reactions
Increase entropy.
Nonspontaneous reactions
Coupling
Phosphorylation
Protein Kinases
ATP provides the energy to drive virtually all the body’s endergonic reactions.

5. Gibbs free energy
Free energy—the portion of a system’s energy that can perform work when temperature and pressure are held constant. The Earth’s free energy ultimately comes from the sun.
Delta G=delta H – [T (delta S)]
Delta H==change in the systems enthalpy or total energy
Delta S==Change in the system’s entropy or disorder.
T==Kelvin or absolute Temperature.
Only processes with a negative delta G value are spontaneous.
In spontaneous reactions either energy must be released from the system or order must be given up (entropy increased).
ATP undergoing hydrolysis to ADP has a ΔG = -13J (releases energy); ADP undergoing dehydration synthesis to ATP has a ΔG = 13J (requires energy).The energy needed to make this bond comes from the “free” e in our food as it is broken down. ADP is recycled back to ATP.

6. Gibbs Free Energy
How does life on Earth not violate the 2nd law of thermodynamics?
Earth is not a closed system. There is a constant input of energy from the sun.
Show Anderson Video 3:39.
A –delta G value indicates that the released energy can be used to do work.
A + delta G value indicates that work must be done on the system to force the nonspontaneous reaction to occur.
We get the energy to create biological order from our food. By oxidizing food molecules, Gibbs free energy is made available to make nonspontaneous reactions occur.

7. Total Energy—delta H—Discuss example of potential energy on a slide.
Need some activation energy to get something going down the slide, but once it starts the potential energy decreases.

8. Entropy
Disorder—spontaneous reactions increase entropy (disorder) delta S, often because they release heat.

9. Temperature
Higher temperatures make reactions more likely to happen. Decrease delta G. Use the Kelvin temp. in Gibbs free energy calculations.

10. Reactions -delta G +delta G Spontaneous Exergonic Increases entropy
Example: Creation of ATP
+delta G
Nonspontaneous
Endergonic
Decreases entropy
Example: Breakdown of ATP

11. Example Problem
An experiment determined that when a protein unfolds to its denatured state from the original folded state, the change in enthalpy (delta H) is J/mole and the change in entropy (delta S) is 275 J/(moles x Kelvin). Calculate the change in free energy that occurs if the protein unfolds at a temperature of 20 degrees Celsius?
Is this reaction spontaneous or nonspontaneous?
Is the reaction endergonic or exergonic?
Does the reaction increase or decrease entropy?

12. Example Problem 2

15. Chemiosmosis
Chemiosmosis is the diffusion of hydrogen ions (protons) across the biological membrane via the ATP synthase (a transport protein) due to a proton gradient that forms on the other side of the membrane. The proton gradient forms when the hydrogen ions accumulate as they are forcibly moved to the other side of the membrane by carrier proteins while the electrons pass through the electron transport chain in the membrane. Since more hydrogen ions are on the other side they tend to move back across the membrane via the ATP synthase. As they flow through energy is released which is then used to convert ADP to ATP (by a process called phosphorylation).

16. Chemiosmosis-in photosynthesis

17. Chemiosmosis—Cellular Respiration