Use matlab ode45 to integrate set of diff. equations

Use of ode45 to complete this...however, I am not sure how to go about it.

1.) integrate set of diff. equations with given initial conditions and constants and plot concentration profiles of all 5 dependent variables
2.) plot phase plot of s1 vs s2. What does the phase plot demonstrate? ...I don't know?
3.) perform a stability analysis examining the eigenvalues (matlab eig function) of Jacobian matrix around the steady state.

Please see attached