Carol W. Greider

Carol is a scientist. She studies how tiny parts of life work.

Carol found a special helper in cells. This helper fixes the ends of our tiny body parts. Without this help, those parts get too short.

When the parts get short, cells can get sick. Carol's work helps us learn about this. She studied a tiny living thing in water to find it.

Carol won a very big prize for her work. It is called a Nobel Prize. She is a great teacher too.

Carol Greider is a famous scientist. She studies how cells work. She is a molecular biologist. This means she studies the tiny parts inside living things.

In 1984, Carol made a big discovery. She found an enzyme called telomerase. An enzyme is a helper that makes changes in cells. This helper works on chromosomes. Chromosomes are the parts that hold our DNA.

Every time a cell divides, chromosomes get shorter. Telomerase helps by rebuilding the tips of the chromosomes. These tips are called telomeres. Telomeres protect the ends of the chromosomes. Without this help, the ends could get too short. This can cause cells to stop working or get sick.

Carol used a tiny water creature to study this. It is called Tetrahymena. She also studied mice and yeast. Her work helped us understand how cells age.

Because of her work, Carol won the Nobel Prize in 2009. This is a very big prize for science. She has taught at many great schools. Now, she is a professor at UC Santa Cruz. Her lab studies how these tiny parts connect to disease.

Carol Greider is a famous molecular biologist. She studies the tiny parts that make up living things. Her work helps us understand how cells live and age. Greider is a professor at the University of California, Santa Cruz. She also earned many big awards for her hard work. One of the most famous is the Nobel Prize in Physiology or Medicine.

Greider discovered a special helper called telomerase. This helper is an enzyme. An enzyme is a tool that makes changes in a cell. Inside cells, there are chromosomes that hold DNA. At the ends of these chromosomes are tips called telomeres. Every time a cell divides, these tips get shorter. Telomerase works by rebuilding those tips. This prevents the chromosomes from getting too short.

Greider began her big discovery as a student. She studied at the University of California, Berkeley. She worked with a teacher named Elizabeth Blackburn. In 1984, they looked for this enzyme in a tiny water creature. This creature is called Tetrahymena thermophila. It is a small organism that lives in fresh water. On December 25, 1984, Greider found results that pointed to the enzyme.

Greider has done much more research since then. She studied how telomerase works in mice and yeast. In 1990, she showed how shortening telomeres can lead to cellular senescence. This is a way cells stop growing. She also helped create the first telomerase knockout mouse. This helped scientists see what happens when telomerase is missing. Her work shows how short telomeres can lead to premature aging.

Greider faced many hard jobs in her life. She has dyslexia, which is a way of reading differently. This made it hard for her to take some school tests. She applied to thirteen graduate schools. Only two schools, Caltech and Berkeley, accepted her. She chose to go to Berkeley to study. Her dyslexia helped her see patterns in new ways. This helped her become a great scientist.

Carolyn Widney Greider is a prominent American molecular biologist. She is a Distinguished Professor at the University of California, Santa Cruz. Greider is most famous for discovering telomerase, a vital enzyme in living cells. This discovery earned her the 2009 Nobel Prize in Physiology or Medicine. She shared this honor with Elizabeth Blackburn and Jack W. Szostak. Her work has provided deep insights into how cells age and how they can become diseased.

To understand Greider's work, one must understand chromosomes. Chromosomes are structures that hold genetic information. At the very ends of these chromosomes are protective caps called telomeres. Telomeres consist of specific DNA sequences, such as a six-base pair motif. During DNA replication, the cell copies its genetic code to divide. However, this process causes the telomeres to shorten slightly each time. Without protection, chromosomes would eventually deteriorate. This shortening can lead to senescence, which is when cells stop dividing. It can also cause cancer-causing chromosome fusion.

Greider discovered how cells prevent this deterioration. She identified an enzyme called telomerase, which was originally named telomere terminal transferase. Telomerase acts as a rebuilding tool for the chromosome tips. It adds extra DNA bases to the ends of the telomeres. This mechanism determines the lifespan of a cell. Greider found that telomerase uses an RNA component as a template. She proved this by using RNA degrading enzymes in her research. When the RNA was removed, the telomeres stopped extending. This showed that the enzyme relies on RNA to build the DNA repeats.

Greider's discovery happened while she was a graduate student at the University of California, Berkeley. She worked in the laboratory of Elizabeth Blackburn. They chose to study a model organism called Tetrahymena thermophila. This is a small, single-celled protozoan that lives in fresh water. It was an unusual choice, but it has a large number of telomeres to study. On December 25, 1984, Greider obtained results that suggested a specific enzyme was responsible. After six more months of research, the discovery was confirmed. They published their major findings in the journal Cell in December 1985.

Since her initial discovery, Greider has expanded her research into many different systems. In 1989, she cloned the gene for the RNA component in Tetrahymena. She later showed that telomerase is processive, meaning it can add multiple repeats in one go. In 1990, she worked with Calvin Harley to link telomere shortening to cellular senescence. She also studied how telomeres behave in yeast, specifically Saccharomyces cerevisiae. In these yeast cells, she found that short telomeres trigger a DNA damage response. This research helps scientists understand the fundamental rules of cell biology across different species.

Greider has also conducted significant research using mice to study human-like biology. In collaboration with Ronald A. DePinho, she produced the first telomerase knockout mouse. A knockout mouse is an organism where a specific gene has been made inoperable. This allowed scientists to see what happens when telomerase is missing. The results showed that while telomerase is not strictly required for life, its absence causes problems. These mice showed various deleterious phenotypes, often called premature aging. Greider even observed that by the sixth generation, these mice became entirely sterile.

Greider's journey to scientific success included personal challenges. She has dyslexia, a condition that affects how the brain processes written language. This made standardized tests, like the GRE, difficult for her. She applied to thirteen different graduate schools but was only accepted by two. These were the California Institute of Technology and UC Berkeley. Greider chose Berkeley, and her dyslexia eventually became a scientific asset. She credits her ability to intuit complex, simultaneous processes to her compensatory skills. This unique way of thinking helped her make unusual and successful decisions in her career.