Ada Yonath is in demand. People come from far and wide to hear her speak, she has been the subject of many an interview, and the media have camped outside her daughter's home. Her shock of grey, curly hair is now well known in Israel, and the great and the good have queued up to praise her.

All of which is astonishing considering Yonath has spent practically her entire career in a lab, researching a decidedly unglamorous and obscure subject at Israel's Weizmann Institute.

That anonymity evaporated the moment she beat large, well-funded teams from other countries to produce breakthrough research on the structure of the ribosome - and won the Nobel prize for chemistry in 2009.

If you have never studied advanced biochemistry, it is probable that you have never heard of ribosomes. However, you would not exist without them. Yonath, in London to address a scientific meeting on the chemical origins of life, laughs when I ask her to tell me exactly what a ribosome is, the implication being that I would need to cancel all holidays and spend a month surrounded by text books. Their basic function is fairly simple to grasp, though.

Ribosomes exist in the cells of all organisms. They turn information held in DNA into proteins necessary for life, a process is known as "translation". Yonath explains: "DNA is a code of four letters, proteins are made up of amino acids which come in 20 forms. So the ribosome is a very clever machine that reads one language and operates in another."

But the structure of the ribosome remained a mystery until Yonath found a solution using a complicated process known as crystallography. She says: "The procedure is physics, the maths is a very high level, the question is biology and the answer is expressed in chemistry. My first contribution was to crystallise the ribosome which had been tried by many, all of whom failed."

Thanks to Yonath we now have much greater understanding of the ribosome. But did she have an application in mind? "People always talk about the implication and applications of a process, but for me the goal is purely about knowledge. Knowledge can become practical today, in 20 years or in 500 years. Ask Newton. He didn't know there would be space research based on his accident with the apple."

Although it may not have been the aim, in this case there has been a very important practical application of her research. In recent years, the medical community has been concerned about the growing phenomenon of resistance to antibiotics which reduces the efficacy of anti-bacterial drugs. The work she has been doing could provide answers to creating more effective antibiotics.

Yonath's achievements as a scientist are even more remarkable given the obstacles she faced in her early life. She was born in Jerusalem in 1939 into a poor family. Life was tough but it became even harder when her father died when she was just 11. "We moved to Tel Aviv to a two-room apartment. In one room were my mother, my sister and me. The other room was let to three students. I had to clean their room and make their breakfast and also take my sister to school. Then in my own school I coached students in mathematics and chemistry. I did lots of other jobs too. From the age of 11 I was cleaning floors, washing dishes, making sandwiches and being a cashier. Survival was the name of the game. Life was so hard that I had to struggle to keep up my standards. Under these conditions I didn't think about science too much."

The decision to study chemistry was a practical rather than an idealistic one. "My mother was not well and I had to take care of her so I decided to do something where I could get home frequently and easily. I thought: science was interesting - why shouldn't I go somewhere and study. I went to university. It was nearby so I could not only support myself but my mother too."

Despite her success against the odds, Yonath certainly does not regard herself as a female role model. "I don't see myself as a soldier for other women. Some people say I got the prize because I was a woman – so it's like I'm a victim. Somehow I don't think the Nobel committee went to meetings for all those years and decided deliberately not to give the prize to a woman, so why would it happen the other way around?"

When the prize did come it was vindication for Yonath, who for years had been disregarded in her native country. "People didn't believe in me at the beginning. My results were minute. It was a difficult process to explain and there were people who thought I didn't know what I was doing. I was described as a dreamer, a fantasist, even as the village idiot. I didn't care. What I cared about was convincing people to allow me to go on with my work."

Not that she quite believed it when she won. She laughs: "I told the guy who phoned me up with the news that he probably had too much to drink. "

The following morning, she realised there must be a reason why dozens of reporters were camped outside her daughter's house where she was staying at the time. She was happy to be a Nobel winner, mainly because it gave her the opportunity to continue in her work. But as prizes go, the Nobel ranks second in importance for her.

"My granddaughter also gave me a prize," she says. "It was the grandmother of the year award. I've got it for the past five years now. That makes me the most happy."