You are studying the degradation properties of a polymer sample in vitro and in vivo and

generate the below table of molecular weight data.

Assume that the polymer degrades according to pseudo$-$first order reaction kinetics, i$.$e$.$

$[$M$]=[$M$]\_0$ e$-$kt

where: $[$M$]=$ molecular weight of the polymer at a given time, t

$[$A$]\_0=$ initial polymer molecular weight

k $=$ reaction rate constant

a$)$ Showing your steps, calculate the molecular$-$weight half$-$life of the polymer sample in

vitro and in vivo $($Hint: use graphs and equations$)$

b$)$ Why might the degradation rates of the polymer be different in vitro and in vivo?