Cell Information

2 Pages 475 Words

Chapter 6 Energy Flow in the Life of a Cell
I. Energy is the capacity to do work
Uses of energy in living things
1. Mechanical work ¨C movement
2. Biosynthetic work ¨C metabolism
3. Transport work ¨C getting things in and out of cells
I. Energy is the capacity to do work
Types of Energy
1. Potential energy¡ªstored energy
2. Kinetic energy¡ªenergy of movement
3. Potential and kinetic energy can exist in many forms: mechanical, chemical, electrical, heat, etc.
II. Thermodynamics
First law of thermodynamics
Energy cannot be created or destroyed
Total energy remains the same although it may change form

How does this relate to ¡°conservation of weight¡± described by Professor Morrison?
II. Thermodynamics
Second law of thermodynamics
When energy is converted from one form to another, the amount of useful energy decreases
Any spontaneous change causes a more uniform distribution of energy resulting in less useful forms of energy
Unless energy is added to a system, spontaneous processes result in increases in randomness and disorder. Also, called entropy
II. Thermodynamics
Second law of thermodynamics
Organization of matter and energy
Concentrated energy is more ordered (complex) chemically
The six carbon atoms of glucose (a simple sugar) are much more ordered (and therefore contain more potential energy, than the six carbon atoms found in the randomly moving carbon dioxide molecules formed when our cells process glucose ¨C (our cells extract some of that useful energy)
III. Energy use in living things
Energy is stored in the chemical bonds of biomolecules; for example glucose as indicated on previous slide
How is this stored energy released so work can be accomplished?
To answer this question we must understand Exergonic and Endergonic reactions

III. Energy use in living things
Energy releasing chemical reactions are exergonic
1. High energy reactants ¡ú low energy products
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