| Question | Answer |
| endergonic | Positive ∆G values. |
| exergonic | Process has a negative ∆G. |
| How does ∆G affect the rate of reaction? | No bearing |
| when ∆G=0, what is the state of the system? | the process is at equilibrium and there is no net flow either in the forward or reverse direction. |
| Gibbs free energy equation | G = H - TS. At constant pressure and temperature: ∆G = ∆H - T∆S. |
| What value tells you if the reaction will proceed as written? | Gibbs free energy, G. Any process with nonzero ∆G proceeds spontaneously to a final state of lower free energy. (Whichever writing of the equation makes ∆G negative) |
| third law of thermodynamics | Entropy of any crystalline, perfectly ordered substance much approach zero as the temperature approaches 0 K and, at T = 0 K, entropy is exactly zero. |
| negentropy | The negative entropy changes that confer organization and information content to living organisms. More ordered system more organized and possesses greater information content. |
| energy dispersion | What entropy represents, the dispersion of energy among a large number of molecular motions relatable to quantized states (microstates) |
| what values of ∆S are favored in reactions? | large positive |
| entropy | Measure of disorder and randomness in the system. Organized or ordered state is low-entropy. |
| equilibrium | A state of minimal potential energy. |
| second law of thermodynamics | 1. Systems tend to proceed from ordered (low-entropy or low-probability) states to disordered (high-entropy or high-probability) states. 2. The entropy of the system plus surroundings is unchanged by reversible processes. The entropy of the system plus surroundings increases for irreversible processes. 3. All naturally occurring processes proceed toward equilibrium. Energy flows spontaneously so as to become diffused or dispersed or spread out. Energy dispersal results in entropy increase. |
| ∆Hº’s consequences on protein folding | Positive values of ∆Hº expected for breaking of hydrogen bonds as well as for exposure of hydrophobic groups from the interior of the native, folded protein during the unfolding process. Therefore, folded state strongly favored. |
| calorimeter | Experimentally determines enthalpy changes for biochemical processes. |
| standard state | For solutes in a solution, standard state is normally unit activity (often simplified to 1 M concentration) Symbolized by “º”. |
| Compare ∆H and ∆E | ∆E = heat transferred in a constant volume system. ∆H = heat transferred in a constant pressure process. Often essentially equal though, because volume changes are typically quite small. |
| enthalpy | (H) H = E + PV. Used for constant pressure processes |
| What is the equation for w? | w = -P∆V where P is the pressure and ∆V is the volume change and is equal to V2 - V1. |
| Mechanical work | Movement through some distance caused by the application of a force. Both movement and force required for work to have been done. |
| What is the equation of ∆E? | ∆E = E2 - E1 = q + w Where q: The heat absorbed by the system from the surroundings. w: the work done on the system by the surroundings. |
| What are the only two ways that internal energy can change? | If energy flows in or out in the form of heat or work. |
| state function | Internal energy depends only on the present state of a system. Independent of pathway. |
| internal energy | (E or U) Includes all the energies that might be exchanged in physical or chemical processes. Eg. rotational, vibrational, translational energies of molecules and also energy stored in covalent and noncovalent bonds. |
| First law of thermodynamics | Total energy of an isolated system is conserved. All forms of energy could ultimately be converted to some other form. |
| what type of system are living things, typically? | open |
| open system | May exchange matter, energy or both with its surroundings. |
| closed system | May exchange energy, but not matter |
| isolated system | Cannot exchange matter or energy with its surroundings |
| three kinds of systems | isolated, closed and open |
| surroundings | Everything else in the universe outside the system |
| system | Portion of the universe with which we are concerned |
| thermodynamics | Whether or not a process with occur spontaneously. Three laws |
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