In biochemistry, an Eadie–Hofstee diagram (also Woolf–Eadie–Augustinsson–Hofstee or Eadie–Augustinsson plot) is a graphical representation of enzyme kinetics in which reaction velocity is plotted as a function of the velocity vs. substrate concentration ratio: <math>v = -K_m { V \over [S] } + V_\max</math> where v represents reaction velocity, Km is the Michaelis–Menten constant, [S] is the substrate concentration, and Vmax is the maximum reaction velocity.

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  • In biochemistry, an Eadie–Hofstee diagram (also Woolf–Eadie–Augustinsson–Hofstee or Eadie–Augustinsson plot) is a graphical representation of enzyme kinetics in which reaction velocity is plotted as a function of the velocity vs. substrate concentration ratio: <math>v = -K_m { V \over [S] } + V_\max</math> where v represents reaction velocity, Km is the Michaelis–Menten constant, [S] is the substrate concentration, and Vmax is the maximum reaction velocity. It can be derived from the Michaelis–Menten equation as follows: <math>v = {{V_\max [S]} \over {K_m + [S]}}</math> invert and multiply with <math>V_\max</math>: <math> {V_\max \over v} = {{V_\max(K_m+)}\over{V_\max[S]}} = {{K_m+[S]}\over{[S]}}</math> Rearrange: <math> V_\max = {{{vK_m} \over {[S]}} + {{v[S]} \over {[S]}}} = {{vK_m}\over {[S]}} + v</math> Isolate v: <math>v = -K_m{v \over {[S]}} + V_\max</math> A plot of v vs v/[S] will yield Vmax at the intercept with the y-axis and the slope is −Km . Like other techniques that linearize the Michaelis–Menten equation, the Eadie-Hofstee plot was used historically for rapid identification of important kinetic terms like Km and Vmax, but has been superseded by nonlinear regression methods that are significantly more accurate and no longer computationally inaccessible. It is also more robust against error-prone data than the Lineweaver–Burk plot, particularly because it gives equal weight to data points in any range of substrate concentration or reaction velocity. (The Lineweaver–Burk plot unevenly weights such points. ) Both plots remain useful as a means to present data graphically. One drawback from the Eadie–Hofstee approach is that neither ordinate nor abscissa represent independent variables: both are dependent on reaction velocity. Thus any experimental error will be present in both axes. Furthermore, the typical measure of goodness of fit, the correlation coefficient R, is not applicable.
  • El diagrama de Eadie-Hofstee, también llamado de Woolf-Eadie-Augustinsson-Hofstee o de Eadie-Augustinsson, es una representación gráfica de la función matemática utilizada en bioquímica en el estudio de la cinética de las reacciones enzimáticas, por la que se relaciona la velocidad de una reacción con la concentración del sustrato: <math>v = -K_m { v \over [S] } + v_{max}</math> donde 'v' representa la velocidad de la reacción, 'Km' es la constante de Michaelis-Menten, [S] es la concentración del sustrato y 'vmax', es el máximo de la velocidad de la reacción. El diagrama puede deducirse de la ecuación de Michaelis-Menten como sigue: <math>v = {{v_{max} [S]} \over {K_m + [S]}}</math> si se invierte y multiplica por <math>v_{max}</math>, se obtiene: <math> {v_{max} \over v} = {{v_{max}(K_m+)}\over{v_{max}[S]}} = {{K_m+[S]}\over{[S]}}</math> que reordenando: <math> v_{max} = {{{vK_m} \over {[S]}} + {{v[S]} \over {[S]}}} = {{vK_m}\over {[S]}} + v</math> al aislar V, se obtiene: <math>v = -K_m{v \over {[S]}} + v_{max}</math> De manera similar a otras técnicas que permiten linearizar la ecuación de Michaelis-Menten, el digrama Eadie-Hofstee permite visualizar rápidamente los parámetros cinéticos importantes como Km y vmax a la vez que está menos afectada por el margen de error que el diagrama de Lineweaver-Burke, debido a que asigna el mismo peso a todos los puntos para cualquier rango de concentración del sustrato o de la velocidad de reacción. Una de las consecuencias de la aproximación de Eadie-Hofstee es que tanto la variable en la ordenada como en la abscisa no son independientes, sino que dependen de la velocidad de la reacción. De éste modo, cualquier error experimental se encuentra presente en ambos ejes.
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  • In biochemistry, an Eadie–Hofstee diagram (also Woolf–Eadie–Augustinsson–Hofstee or Eadie–Augustinsson plot) is a graphical representation of enzyme kinetics in which reaction velocity is plotted as a function of the velocity vs. substrate concentration ratio: <math>v = -K_m { V \over [S] } + V_\max</math> where v represents reaction velocity, Km is the Michaelis–Menten constant, [S] is the substrate concentration, and Vmax is the maximum reaction velocity.
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  • Eadie–Hofstee diagram
  • Diagrama de Eadie-Hofstee
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