What is the reaction between a copper anode and a zinc cathode?
Well the standard galvanic cell with $\ce{Zn}$ and $\ce{Cu}$ would usually look something like this, assuming there's a salt bridge.



and the reaction could be written as 

\begin{align}
\ce{Cu^{2+}_(aq) +2e^{-} &amp;&lt;=&gt; Cu^0} &amp; E^\circ &amp;=0.34\\
\ce{Zn^0 (s) &amp;&lt;=&gt; Zn^{2+} (aq) +2e^-}&amp; E^\circ &amp;=+0.76\\
\ce{Cu^{2+}(aq) + Zn^0 (s) &amp;&lt;=&gt; Cu^0 (s) + Zn^{2+}(aq)} &amp; E^\circ &amp;= +1.10 
\end{align}

As for your measured emf, that can be calculated using the Nernst Equation.