Statistical Test

I am comparing/investigating the effect of temperature on the actvitiy of non-immobilized lactase and on the activity of immoblized lactase.

I've ended up with 2 sets of data.

The average glucose produced against temperature (5 different temperatures!).

Which statistical test should I do?

I've had a look at Mann-Whitney U test, t-test (paired and unpaired) and Spearmans rank. I've managed to do Spearmans rank for each individual data set, would it be valid to compare the correlation coefficients?
The t-test doesn't make much sense to me, I'm not sure if my data is paired or not.

Thanks