{ diff(x1, t) = (1*k24*k1*x5*x2/((k12 + x2)*(1 + k6*x4)) + 1*k24*k2*x1*(1 - k4*x1)/(1 + k6*x4) + (-1)*k24*k3*x1 + (-1)*k24*k8*x2*x1)/k24,
  diff(x2, t) = (1*k24*k9*x2*(1 + k6*x4)*(1 - k10*x2)/(1 + k7*x3) + (-1)*k24*k11*x3*x2/(k14 + x2))/k24,
  diff(x3, t) = ((-1)*k24*k16*x3 + 1*k24*(k19*x1 + k22)*x2/((k12 + x2)*(1 + k6*x4)))/k24,
  diff(x4, t) = ((-1)*k24*k17*x4 + 1*k24*(k20*x1 + k22)*x2/(k12 + x2) + 1*k24*k21*x2^2/(k13^2 + x2^2))/k24,
  diff(x5, t) = ((-1)*k24*k15*x5 + 1*k24*(k18*x1 + k22)*x2/((k12 + x2)*(1 + k6*x4)))/k24 }