5.1.5 Substrates are bound to enzymes by multiple weak(noncovalent) attractions. 5.1.6 Active sites are clefts or crevices with a generally nonpolar character (polar residues, when present in the active site, usually participate in the catalytic processes, thus called catalytic groups)(or specificity of binding). 5.1.7 The active sites of some unbound enzymes are complementary in shape to those of their substrates(the lock-and-key metaphor, Emil Fisher). 5.1.8 In many enzymes the active sites have shapes complementary to those of their substrates only after the substrates are bound(the induced fit, Daniel Koshland)
5.1.5 Substrates are bound to enzymes by multiple weak (noncovalent) attractions. 5.1.6 Active sites are clefts or crevices with a generally nonpolar character (polar residues, when present in the active site, usually participate in the catalytic processes, thus called catalytic groups) (or specificity of binding). 5.1.7 The active sites of some unbound enzymes are complementary in shape to those of their substrates (the lock-and-key metaphor, Emil Fisher). 5.1.8 In many enzymes, the active sites have shapes complementary to those of their substrates only after the substrates are bound (the induced fit, Daniel Koshland)
5.2 The existence of ES complexes has been shown in a variety of ways 5.2.1 The saturation effect: at a constant concentration of an enzyme, the reaction rate increases with increasing substrate concentrations until a vmax is reached 5.2.2 ES complexes have been directly observed by electron microscopy and X-ray crystallography
5.2 The existence of ES complexes has been shown in a variety of ways. 5.2.1 The saturation effect: at a constant concentration of an enzyme, the reaction rate increases with increasing substrate concentrations until a Vmax is reached. 5.2.2 ES complexes have been directly observed by electron microscopy and X-ray crystallography
Dihydrofolate reductase, NADP+(red) tetrahydrofolate(yellow) The lack of perfect complementarity is important to enzymatic catalysis(induced fit)(not evident in this figure)
Dihydrofolate reductase, NADP+ (red), tetrahydrofolate (yellow) The lack of perfect complementarity is important to enzymatic catalysis (induced fit) (not evident in this figure)
6. Binding energy is the major source of free energy used by enzymes to lower the activation energies of reactions 6.1 Binding energy(Agb) is the energy derived from enzyme-substrate interaction. 6.1.1 Formation of each weak interaction in the ES complex is accompanied by a small release of free energy. 6.1.2 Weak interactions are maximized when the substrate is converted to the transition state 6.1.3 The weak interactions that are formed only in the transition state are those that make the primary contribution to catalysis: Transition state theory. In another words, the enzyme is evolved (designed")to bind the transition state structure
6. Binding energy is the major source of free energy used by enzymes to lower the activation energies of reactions. 6.1 Binding energy (Gb ) is the energy derived from enzyme-substrate interaction. 6.1.1 Formation of each weak interaction in the ES complex is accompanied by a small release of free energy. 6.1.2 Weak interactions are maximized when the substrate is converted to the transition state. 6.1.3 The weak interactions that are formed only in the transition state are those that make the primary contribution to catalysis: Transition state theory. In another words, the enzyme is evolved (“designed”) to bind the transition state structure