The Command Window displays the concentrations of the intermediates during the time course. Scroll

up in the Command Window to see the entire set of time points. The columns are:

Column $1$time $($s$),$ col $2$A$,$ col $3$B$,$ col $4$C$,$ col $5$D$,$ col $6$E $($all concentrations in mM$)$

a$.$ Do A$,$ B$,$ C$,$ D & E reach equilibrium in this time frame? How do you know? Explain $($Note: Consider $2$

figures in the concentrations of each intermediate to be significant. The other figures are insignificant.

For example: For $4\mathrm{.}8692,4\mathrm{.}9$ is significant. For $0\mathrm{.}08113,0\mathrm{.}081$ is significant.$)$

b$.$ If so$,$ about how long did it take for each intermediate to reach equilibrium? Explain.

c$.$ Make a bar graph in which the equilibrium concentration of each intermediate is given by the height

of the bar.

$2.$ Make step $2($B $$ C$)$ rate$-$limiting by decreasing both k$2$ and k$2$r in the model file by $1000-$fold. First,

always clear your workspace, figure, and command window with:

$$clear$,$clc$,$ and $$clf$$

In your model file, enter:

k$2=0\mathrm{.}060$;$($units are s$-1)$

k$2$r $=0\mathrm{.}060$;

All other rate constants should be the same as before.

In your run file, increase the time span to $150$ seconds:

tspan $=[0$:$1\mathrm{.}5$:$150]$;

Run the program again. $($If you get an error, it is most likely because the run file was not the active file

when you hit Run.$)$

a$.$ Have the equilibrium concentrations of A$,$ B$,$ C$,$ D or E significantly changed? Why or why not?

b$.$ Why did it take so much longer for the process to reach equilibrium starting from the same initial

concentrations?

$1234$

A $$ B $$ C $$ D $$ E