Question

Know how Gibb’s free energy and entropy provide energy to cells.

Answer 1

cells are isothermal in nature that means they function at constant temperature and pressure. Heat flow is not a major source of energy as heat flow can only act as a source of work when it passes through a zone of low temperature. the energy that cells can use is termed as The Gibbs free energy. The Gibbs free energy of a system is a measure of the amount of usable energy in that system.

Gibbs free energy change equation, ΔG can be calculated from

ΔG=ΔH−TΔS

here,

• ∆H is the enthalpy change. Enthalpy refers to energy stored in bonds, and the change in enthalpy is the difference in bond energies between the products and the reactants. A negative ∆H means heat is released while a positive ∆H means heat is absorbed.

• ∆S is the entropy change of the system during the reaction. If ∆S is positive, the system becomes more disordered during the reaction and If ∆S is negative, it means the system becomes more ordered.

Reactions with a negative ∆G release energy mean that they can continue without an energy input (are spontaneous).whereas, reactions with a positive ∆G need an input of energy in order to take place (are non-spontaneous).

both the enthalpy change and the entropy change contribute to the overall sign and value of ∆G. When a reaction releases heat (negative ∆H) or increases the entropy of the system, these factors make ∆G more negative. On the other hand, when a reaction absorbs heat or decreases the entropy of the system, these factors make ∆G more positive.