L20-21 Biophysics: Thermodynamics Flashcards
Internal energy (U) is the capacity of a system to…
Do work 🏋️♀️
The first law of thermodynamics states that the energy released from a chemical reaction will…
Transfer heat and do work on its surroundings!
In a closed system it is easy to measure both work and temperature. In open systems it is hard to measure work. Biological systems are ( open / closed )
Open
Enthalpy change is used as synonymous with energy change in biological systems as…
It is hard to measure work done by open systems
To determine if a reaction is favourable we must consider (2)…
Enthalpy and entropy
Moving from solid → liquid → gas , entropy is ( increasing / decreasing / not changing )
Increasing
Boltzman formula
S = k log W
Defines entropy in terms of the Boltzman constant (k) multiplied by the log of the number of accessible microstates (W)
Gibbs free energy (G) combines the effects of…
Entropy and enthalpy
Change in Gibbs free energy formula
ΔG = ΔH - T ΔS
An important biological example of a process driven by entropy is…
Protein folding
The cell carries out unfavourable reactions by coupling them with…
Favourable ones!
An example of a coupled reaction is the synthesis of ATP (unfavourable), which is coupled to…
H+ ion movement across the membrane (favourable)
Why don’t energetically favourable reactions occur spontaneously?
Activation is required to reach the transition state first
Enzymes place reactants in…
Favourable configurations for a reaction to occur
