Personal Column: Back to school

I was coming to the end of university and hadn't made a final decision about what I wanted to do next when I went to a presentation by Teach First. I was studying genetics at Nottingham University, but had always thought about teaching. One of the attractions for me was that it was going to be a real challenge. Teach First places teachers in disadvantaged secondary schools, and I went to a private school in Bath so my experience of an inner-city London comprehensive was very, very limited.

I applied online and was invited to come to an interview day. I had to prepare a seven-minute lesson. When I received a phone call offering me a place I was really excited. I went on a six-week residential course over the summer with the other graduates who had been selected. We had lectures each day in small groups - it was extremely intensive. There were classes on how to conduct yourself around school and deal with particular kids, as well as on the subject you were going to teach.

I started at Quintin Kynaston School, near Swiss Cottage in London, in 2003. It's an inner-city comprehensive where about 70 different languages are spoken in the playground. All of the Teach First schools have to have a minimum of one third of their pupils on free school meals. Two- thirds of the kids at Quintin Kynaston were on free school meals. There were about 1,600 pupils and about 100 staff. It was completely different from my school.

I taught science to 11- to 18-year-olds and biology at A-level. Teaching my first lesson was a huge adrenalin rush. We did name games and talked about what we were going to cover. The challenge for me at the beginning was getting used to the fact that, no matter how carefully you planned everything, there was always some eventuality that you simply did not expect to happen, such as a student bursting into floods of tears, arguments at the back of the classroom, pens being thrown around or the fire alarm going off. During my first few lessons there was a kid whom I had to recommend for anger management because he had a bit of an argument with somebody in one of the lessons.

All of the classrooms are locked so you have a set of keys, and it was quite a usual phenomenon for the teacher's keys to be nicked from the front desk. I think that one of my lowest points was keeping a whole class back at the end of one day because something has been taken and nobody was fessing up. It was a standard procedure to go through kids' bags and if they keys weren't there we had to let them go.

There was a lot of support from the management. I was frightened at times. I had one student in particular who made my life very difficult for the first two terms - the same was true for all of the teachers. She had a very aggressive approach to life. For whatever reason she left.

My favourite time was when we organised a science fair. It was an opportunity for all of the kids to get involved in something science-related, which really interested them. It culminated in a big afternoon where we had a barbecue and prizes for the kids. Some local dignitaries came to decide the winner. The enjoyment that came out of the afternoon was so fulfilling.

My favourite statistic, which I still really relish, is that when I went to the school there were only 11 people on the A-level biology course. After I taught it for a year and took over the whole course, we had 60 people on the course.

Teaching was a fantastic learning experience for me. My mum would call it character-building. It was stressful and fun. I learnt an awful lot about myself in those two years, more than I had done at university. It was an opportunity to really see a whole other side of London which if I had come straight into the City I never would have known existed. And it was also an opportunity to feel that I was really contributing.

Placements last two years, at which point participants can continue teaching or pursue another career. At that stage there were provisional links with some of the large corporations. Now all participants are given the opportunity to undertake an internship with one of 70 organisations that support the programme. Throughout my upbringing the whole focus had been going to the City and working for a big corporation. It was ingrained in me and I wanted to see what that involved. The door was left open at the school, and I left to work at Deloitte, the management consultancy. The company has since set up a formal relationship whereby eight people on the programme do a six-week internship there and are guaranteed a job afterwards.

Less than a year after I left the school I heard it was recruiting teachers. I got in touch with the head of my department and said I might come back. I thought about for it for a weekend, but decided to stay in the City as I felt I hadn't given it enough time.

I haven't left teaching totally behind. I volunteer to mark exam papers at Christmas and during the summer. It keeps me in touch with scientific knowledge so that should I want to go back to teaching it wouldn't be so difficult.

Teaching has given me so many transferable skills, such as dealing with the unexpected, time management, getting real life experience and dealing with real people. I was presenting to 30 kids every day, so now if I'm presenting to colleagues I don't find it difficult. I think it set me up for life.

I often go back to the school, and every time I think I want to go back to teaching. But equally the corporate environment in which I'm working has taught me a lot. I can see positives in both of them. I think in the future there's every chance I will go into teaching again.

The City would be more appealing in terms of salary, but I don't know whether that's what I necessarily want. The fantastic thing about teaching is that it has raised questions in my mind about what I want out of life and what's more important.