Just take the train if it's easier. When I've been for interviews they've not cared how I've travelled as long as it's not first class!

Definitely be honest! I'm coming to the end of the Masters year of a 1+3 PhD which I am leaving- the area of research isn't what I want to be in right now and if I'm honest with myself, I accepted the place because the university is so highly rated. I realised after a few months it wasn't for me and have been honest with the supervisors here and with the supervisors at the university where I will begin a new PhD in September. When I went for interview one of the things that did me a lot of favours was that I was completely honest and up front about my decision and why I had made it. In fact, one of the interviewers told me my willingness to be so honest with everyone involved showed great integrity, a great quality for a scientist. You will have to explain it at interview and if it's anything like mine, it'll take up probably half of the time but be brave, stick by your decisions and believe in yourself and it will work out.

I'm currently on a 4 year programme. They are extremely competitive, so if there's only one place left I wouldn't feel terrible about not getting shortlisted! Most only interview people who have or are predicted Firsts too.

For 4 yr PhDs the whole point is that you don't know exactly what you want to do for a PhD so are looking for experience in a range of projects, sometimes within a particular field eg-metabolic disease, and other times within a broader range of topics, say molecular biology. It sounds as if you know what you want to do already so that might be one reason you didn't get shortlisted. Also with many programmes, there are rules on how many students a supervisor can take, and how many years in a row they can take students. Basically, if you did get on the programme there is absolutely no guarantee you would be able to work with one particular supervisor.

If I were you I'd forget getting work experience in hope of getting on the programme next year and instead get in touch with your supervisor of choice expressing an interest in her work. I doubt she'd see it as nagging- most supervisors are only too happy to take on keen and enthusiastic students!

It's definitely possible to get a decent PhD place with a 2.2 supplemented with a good Masters in the biochem field. I know a guy who got a 2.2 then went on to do well in his MRes and managed to get a BBSRC CASE studentship with a year abroad in industry... not bad going! It will be competitive but as long as you know your stuff regarding the field you apply for, you should be okay. One thing I've learned is that a lot of the time it's who you know that's just as important as what you know, so let people know you're looking and ask around your department.