hi,
The 741 with a 5V supply will only give an output of +1.5V thru to 3.5V.
Its a really poor spec OPA
EDIT:
With an input signal like this: (0.2v - 0.4v) and output like this 0.2v - 5v. not only do you have to amplify the signal you have to apply an offset voltage.
eg: when amplified by 12.5 you would get 2.5V thru 5V
so you need to offset the 0.2V part and amplify by 25 , so that would give approx 0V thru approx +5V
The important item is the OPA, you need a rail to rail OPA. they are not expensive.
Look at the MCP6002 datasheet
You are getting no gain because the 741 will not work down to much less than a couple volts from ground input or output when using a single supply voltage. You need a rail-to-rail op amp as Eric stated.