process can occur spontaneously is that the entropy changes of chemical reactions are not readily measured. Furthermore, the criterion of sponta- neity given in equation 2 requires that both the entropy change of the surroundings and that of the system of interest be known. These difficul- ties are obviated by using different thermodynar function called the free energy, which is denoted by the symbol G (or F, in the older literature)
This equation accounts for the kinetic data given in Figure 8-15.At very low substrate concentration, when [S] is much less than KM, V [s]Vmax/KMi that is, the rate is directly proportional to the substrate concentration At high substrate concentration, when [SI is much greater than KM, V=Vmax; that is, the rate is maximal, independent of substrate
Biological Membranes and Transport Biological membranes are made of a lipid bilayer decorated with various proteins and/or carbohydrates. Membranes define the external boundaries of cells and regulate the molecular traffic across that boundary In eukaryotic cells, membranes also divide the internal space into discrete compartments to segregate processes and components
