this is a presentation on telomere and telomerase

1. Welcome All
Presentation for Medical Biology And Ecology
By: Robin Pharswan

2. How to be immortal ?
Immortal means someone or something that
never dies. That also means no wrinkles……girls

3. The Hero
Say hi to TELOMERE
Repetitive DNA sequences at the
ends of all human chromosomes
They contain thousands of
repeats of the six-nucleotide
sequence, TTAGGG

4. What does our hero do?
• They protect the chromosomes.
• They separate one chromosome from another in the DNA
sequence
• Without telomeres, the ends of the chromosomes would be
"repaired", leading to chromosome fusion and massive
genomic instability.

5. In simple terms……….
Degredation
Fusions
Checkpoint
recognition
Telomere cap
Cell Division

6. How is it connected to aging ?
• Every time a cell divides it actually shortens it’s telomeres.
• It is believed that shortened telomeres in mitotic (dividing)
cells may be responsible for some of the changes we
associate with normal aging.
• After a certain number of cell divisions, the telomeres
would be so short as to somehow prevent the cell from
further proliferation--putting it in a state called
senescence. In other words, telomere length offers a clock
for telling a cell's longevity.

7. Visualizing the length of telomeres with age

8. The Sidekick
Say Hi to Telomerase
Telomerase is a ribonucleoprotein
enzyme complex (a cellular
reverse transcriptase)
In humans, telomerase is active in
germ cells, the vast majority of
cancer cells and, possibly, in some
stem cells.

9. What does our sidekick do?
• Telomerase works by adding back telomeric DNA i.e
(TTAGGG) repeats to the ends of chromosomes, thus
compensating for the loss of telomeres that normally occurs
as cells divide.
• Most normal cells do not have this enzyme and thus they
lose telomeres with each division.

10. In simple terms……….
Car running low on
telomere
Replenishes telomere
with help of Telomerase
Gas Station
Telomerase Gas Station
Not Again…..
I will need to fill it
at the gas station
At your service
Hastla la Vista……..

11. The immortality link…
• In the laboratory, cells in tissue culture with introduced telomerase have
extended the length of their telomeres. They have already divided for
250 generations past the time they normally would stop dividing, and
are continuing to divide normally, giving rise to normal cells with the
normal number of chromosomes.
• Research also shows that the counter that controls the wasting away of
the telomere can be "turned on" and "turned off". The control button
appears to be the enzyme telomerase which can rejuvenate the telomere
and allow the cell to divide endlessly. Most cells of the body contain
telomerase but it is in the "off" position so that the cell is mortal and
eventually dies.
• There is experimental evidence from hundreds of independent
laboratories that telomerase activity is present in almost all human
tumors but not in tissues adjacent to the tumors.
• Examples of immortal cells: blood cells and cancer cells

12. Visualizing the telomerase….
• This slide shows cells stained
to visualize the presence of
telomerase.
• The bottom dish was
treated to produce active
telomerase and is still
dividing
• The top dish of normal cells
of the same age has stopped
dividing

13. We can conclude that………
If we are able to control the telomerase in our cells we could
essentially stop all the cells from degrading and ultimately dying. This
is a recipe for immortality. We could live as long as we want
unless……the almighty has some mischief planned for us.
Marvel Super villan
Hell bent at killing half
of all the life in entire
universe.

14. CAUTION
Uncontrolled Telomerase may lead to excessive growth of the cells.
Hence, we need to be careful otherwise we all know we are made of
cells and if things go wrong all that will be left of us would be a
mound of cells……. Not Cool.

15. Thank You
Have a great day ahead !!!
Sources:- Images: Google
Text and info: Slideshare
Rest: Imagination