Lecture 4 - Lecture 4 Cell Functions What is energy...

Lecture 4 – Cell Functions
What is energy?
Capacity to do work
Kinetic
-the energy of motion
---Photons large objects
Potential
-Stored energy
---Chemical of mechanical
The laws of thermodynamics describe the basic properties of energy
-The total energy in a given system remains constant, never created or destroyed
-When energy is converted from one form to another, the total amount of useful
energy decreases.
Conservation of Energy
-Laws of thermodynamics can be stated as the principle of conservation of energy
---Energy can never be created or destroyed, only converted from one form to
another.
Entropy
If energy can’t be created or destroyed, what happens to it?
-Converted to heat!
---Heat is the kinetic energy contained in the random movement of atoms and
molecules
---Entropy is a measure of disorder of molecules (or “randomness”) and increases
when energy changes form
Chemical Energy
-Potential energy contained in molecules of fuel
-Carbs and fats (like gasoline) are rich in chemical energy