A huge influence on her success was a particularly brilliant biology teacher. Take a bow, Peter Gallagher.

Back then, only a handful of people went on to university from the comprehensive school. One student had succeeded in going to Oxbridge in each of the two preceding years.

Ros, the daughter of a taxi driver and a seamstress, was born in Sheffield before the family moved to Riddlesden on the outskirts of Keighley. She read natural sciences at New Hall, then went on to take a PhD in physiology at Leicester University. Her younger sister went to Imperial College, London, making their parents doubly proud.

Ros's room-mate at New Hall was the daughter of a travelling salesman. Another friend's father worked at a builders' merchants. "You were there because you were bright and keen on your subject. No-one was interested in your background," says Ros.

At that time, the ratio of state school-educated students to independent school-educated students was not what it is today. Now, 55 per cent of students at Cambridge are from state schools, and at New Hall the figure is 61 per cent.

Yet, says Ros, an idea persists among some state schools and their pupils that a Cambridge education is not for the likes of them. That's why she and her husband Steve Edwards have endowed New Hall, Cambridge, with £30m to help to widen access to the college for bright students from all backgrounds and to provide an increased number of bursaries for those who might otherwise face financial hardship. Now based in Cambridge, Ros and Steve Edwards have made the biggest ever donation to a Cambridge University college by a British couple. In their honour, the college, which was opened in 1954 and given no "proper" name until the day when it received an endowment from a major donor who would then name it, will be called Murray Edwards College.

The Edwards endowment has fulfilled the dream of the college's founder, the late Dame Rosemary Murray, who had taught at Sheffield University before moving on to Cambridge and later becoming the university's first female vice-chancellor.

Ros Edwards feels that she and her husband, who went to St Edmund Hall, Oxford, have benefited so greatly from their own education that they have always wanted to give something back.

After her studies, Ros, who's now 44, went into computer programming, system design, then project management and consultancy. Along the way, she met Steve Edwards, who was in the same line of business. In 2001, they made a reported £700m from the sale of their software company Geneva Technology.

The couple now invest in small start-up businesses and act as mentors to newer entrepreneurs. The sale of their own company made them also want to give some benefit to their respective universities. Ros's first donation to New Hall was £1m, and during the process she discussed the college's future needs with its president, Anne Lonsdale.

"Anne really felt strongly about widening access," says Ros. "She also wanted to improve facilities, and make more bursaries available. Money is always found somehow to help those who are from a poorer background, but Anne wanted to provide more bursaries, so that money is not a factor in whether a good student from a poorer family decides to go to New Hall.

"We also discussed provision of research fellowships, and it became clear that what was needed was a proper endowment. All of these things were aspects of the running of the college which I had never appreciated when I was a student there.

"New Hall is a wonderful college, which is really good at making everyone feel welcome, and is up at the top of the table in terms of 'value-added', the measurement of how well students do by the end of their time there compared to where they were at the beginning.

"But the college is also one of the comparatively poorer ones at Cambridge, and Steve and I were, luckily, in a position to help."

Apart from wishing to aid the college in wooing bright students from all backgrounds, Ros says she and Steve wanted to help Cambridge to compete on the world stage with other top-class educational institutions like Harvard, where 54 per cent of former students give financial donations to the university after they have graduated.

"As a country we don't have a great deal in the way of natural resources or manufacturing industry. We live by our ideas in areas like biotechnology and IT, and we have thriving industries like film and media.

"Only eight per cent of Cambridge's former students give back to the university, yet such donations help our universities enormously. We all give what we can to charities, but we don't think so readily about giving something back for the education we've received, which helps us to get succeed in life.

"That's why, although we give money to other educational causes, Steve and I decided to do one big transformational thing for a fantastic place which gave me so much."