Ok but do you really have a reason then, for doing a postgrad course? I think it would be better to have an idea what you want to do, for example, you want to work in bioscience doing research. Then you can have a look to see how you would get to that job.
You need to think long and hard about whether going back to university is the right desicion. A lot of people resort to it because they don't want to work or they can't find the right job. In that case, you would be getting yourself into debt for funding a course that might be useful. To be honest funding is going to be hard. There are not many postgrad courses that offer funding and if they do, they will be competitive and with a 3rd you will have a lower chance that someone with a 2.1 or 1st.
What about becoming a teacher? Does that appeal to you in anyway?
I'm still not sure how you feel about research and your area (bioscience).