Question 1

Who is Carol Greider and why is she famous?

Accepted Answer

Carol Greider is an American molecular biologist born in 1961 in San Diego. The key thing to remember is that she discovered telomerase in 1984, an enzyme that protects the ends of chromosomes by lengthening them. This discovery earned her the Nobel Prize in Physiology or Medicine in 2009, shared with Elizabeth Blackburn and Jack Szostak. Imagine that without this enzyme, our chromosomes wear down with every cell division, which is linked to ageing and cancer.

Question 2

What is the historical importance of the discovery of telomerase?

Accepted Answer

The discovery of telomerase transformed our understanding of cellular ageing and cancer. What makes this discovery so decisive is that it explains how cancer cells become “immortal” by reactivating the enzyme. Before Greider, scientists knew that telomeres shortened, but the mechanism that maintained them was unknown. The key point of the episode is that this enzyme now serves as a target for anti-cancer therapies and longevity research.

Question 3

Why was the discovery of telomerase made on a micro-organism?

Accepted Answer

To understand this, you have to remember that Greider was working on Tetrahymena, a single-celled protozoan that has a great many chromosomes and therefore many telomeres. What is striking here is the strategic choice of model organism: Tetrahymena made it easy to observe the enzyme's activity. Less a matter of chance than an informed decision, this choice accelerated the research and allowed a clear demonstration as early as 1984.

Question 4

What was a typical day like for Carol Greider in the laboratory?

Accepted Answer

In the morning, Greider arrived early after dropping her children off at school, read her emails and planned experiments with her team. In the afternoon, she was at the bench: preparing DNA samples, reading electrophoresis gels, discussing results with the PhD students. In the evening, she wrote articles and prepared her classes, all while taking care of her children. What is often forgotten is that she balanced a cutting-edge research career with life as a single mother.

Question 5

Which laboratory object was crucial for visualizing telomerase?

Accepted Answer

The key object is the electrophoresis gel followed by an autoradiograph. The gel separates DNA fragments according to their size, and the autoradiograph reveals their position as bands. It was on one such plate, developed on 25 December 1984, that Greider saw the “ladder” pattern proving the existence of telomerase. Picture her excitement: she danced in the empty laboratory as she realized the importance of what she had just discovered.

Question 6

What does the word “telomerase” mean and how does it work?

Accepted Answer

The word telomerase comes from telomere (the protective end of chromosomes) and the suffix -ase, which denotes an enzyme. What sets this enzyme apart from others is that it carries its own RNA molecule, which serves as a template to build the telomeric repeats. In practical terms, it adds DNA sequences to the ends of chromosomes, preventing them from shortening during cell divisions. The key to how it works is that it acts like a machine for copying telomeres.

Question 7

What famous anecdote surrounds the discovery of telomerase?

Accepted Answer

On 25 December 1984, while she was a 23-year-old student in Elizabeth Blackburn's laboratory, Carol Greider developed an autoradiograph plate and discovered the “ladder” pattern proving the existence of telomerase. What is often forgotten is that she recounted putting on music and dancing in the empty laboratory that Christmas day, sensing the importance of what she had just seen. This anecdote captures the joy of a scientific discovery made in solitude.

Question 8

What was the global scientific context at the time telomerase was discovered?

Accepted Answer

In 1984, molecular biology was booming: the structure of DNA had been known since 1953, DNA sequencing had been invented by Sanger in 1977, and genetic engineering had been born with recombinant DNA in 1973. What makes the context important is that these technical advances provided Greider with the tools she needed to isolate and characterize telomerase. Less a coincidence than fertile ground, this era saw major discoveries about the genome flourish.

Question 9

Which places shaped Carol Greider's career?

Accepted Answer

The key places are the University of California, Berkeley, where she discovered telomerase in 1984, then Cold Spring Harbor Laboratory in New York State, where she ran her own laboratory from 1988. Finally, Johns Hopkins University in Baltimore, where she has been a professor since 1997. The key thing to remember is that these leading institutions gave her the means to carry out her research. It was in Stockholm that she received the Nobel Prize in 2009.

Question 10

What primary source attests to the discovery of telomerase?

Accepted Answer

The fundamental primary source is the article by Greider and Blackburn published in 1985 in the journal Cell, titled “Identification of a specific telomere terminal transferase activity in Tetrahymena extracts.” The key thing to remember is that this article describes for the first time the enzyme activity capable of adding telomeric sequences to the ends of chromosomes. A second article in Nature in 1989 revealed that the enzyme contains an RNA template, explaining its mechanism.

Carol Greider(1961 — ?)

Frequently asked questions

Key Facts

Works & Achievements

Anecdotes

Primary Sources

Key Places

Liens externes & ressources

Références

Rechercher

See also

Related Characters