Cell Information

            Chapter 6 Energy Flow in the Life of a Cell.
            
            
            
            
             Transport work getting things in and out of cells.
            
            
            
            
             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 (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 á low energy products.
             2. Wood burning in a fireplace would be an example.
             Energy requiring chemical reactions are endergonic.
             1. Low energy reactants á high energy products.
             Chemical reactions and activation energy.
             1. Why doesn't the wood spontaneously burn?.
             2. Why did Professor Morrison's jelly doughnuts not burst into flames?.