Molecules and Bioenergetics

Energy can be converted from one form to another, but can neither be created nor destroyed.

In the universe or an isolated system, the degree of disorder only increases.

the release of heat energy

Cells are islands of order in a disorganized world. Biochemical processes that organize the cell simultaneously release heat, thereby increasing the universe’s level of disorder.

during the interconversions of different types of energy

areas within a cell (or from inside and outside) where the charge in molecules is higher in one area and lower in the other; movement of charge across distances that allows work to be done

area of a cell (or from the inside to the outside the cell) where there’s a high concentration of a molecule and somewhere else in the cell, the ion concentration is low; the movement of molecules across distances allows work to be done

stored in chemical bonds, concentration gradients, and as electric potential

Due to the rearrangement of the bonds and how the molecules interact with the surrounding environment, release energy

the energy of a molecule that could be used to do work in a cell

vibration rotation translation (movement) enthalpy

energy stored in chemical bonds

G=H-TS where H = enthalpy; T=temperature in K; S = entropy

Coupling exergonic to endergonic reactions

The reaction is exergonic and energetically favorable.

The reaction is endergonic and energetically unfavorable.

In an exergonic reaction, the Gibbs free energy of the forward reaction decreases. In an endergonic reaction, the Gibbs free energy of the forward reaction increases.

The reaction will occur.

The reaction will not occur.

If the additive DeltaG is negative.

activated carrier

activated carrier

activated carrier