Before revision:  These formulae will be very useful in future in analyzing the data collected during experimental investigations of this phenomenon{\it   .
After revision:  These formulae will be very useful in future in analyzing the data collected during experimental investigations of this phenomenon{\it for the average rate of enzymatic reactions. This generalized Michaelis-Menten-like formula (and the exact analytical expressions for a few other quantities) that we report here display the interplay of four different branched pathways corresponding to selection of four different types of tRNA .