Transcript Scary Tree Template

Chapter 3.4
The Search for New Medicines
Biodiversity and Medicine
• People have always studied plants for
their ability to heal wounds, fight diseases,
and ease pain.
• For ex: aspirin was made from the bark of
the willow tree.
• Almost half of medicine were found in
plants or animals first.
• For ex: Madagascar rose periwinkle has
produced two effective cancer treatments:
one for childhood leukemia, and other one
for Hodgkin’s disease.
GOAL
• In 1995, the American Medical Association
called for the protection of Earth’s
biodiversity.
• Their goal was to preserve the
undiscovered medicines that may
exists in nature.
The story of Taxol
• Plants in many ecosystems can produce
chemicals that protect them from
predators, parasites, and diseases. This
ability results from the plants’ adaptations
to their environment.
• Some protective chemicals that plants
produce can be used to fight diseases in
humans.
The Pacific Yew
• This tree grows in the temperate rain
forest. It is very resistant to many diseases
and insects. Scientists found that bark of
the tree has crystals, called Taxol, that
protects the tree.
Taxol as cancer treatment
Taxol stops cancer cells from multiplying by
forming tiny cages around cancer cells that
prevent them from diving, growing and
spreading in a body.
The supply of Taxol
• Because of a high demand, there is a
problem with supplying of Pacific yew
trees. These trees must have a bark to
live. Three Pacific trees are required to
produce to Taxol for one cancer patient.
• Today, the yew tree is no longer used to
make Taxol.
Synthetic Taxol
Scientists have worked many years to
produce synthetic Taxol in a laboratory, and
they succeeded. Now, cancer patients don’t
have to worry about getting Taxol. And, yew
trees are saved.
Review concepts: How are plants
useful for people? Give an example.
Why is biodiversity protected by
the American Medical Association?
What is Taxol? How is it benefit
people?
What tree provided Taxol?
How is Taxol used nowadays?
Chapter 3.4 Assessment
1a. Why did the American Medical
Association call for the protection of Earths’
biodiversity?
1b. Do you think that scientists have
identified all the wild plants that may have
medical uses? Why or why not?
1c. Suppose many wild plants were to
become extinct within a short time. What
effect might this have on medical research?
Explain your answer.
2a. What adaptations of rain forest plants
make them likely sources of medicines?
2b. What plant is the source of taxol, and
what is the function of taxol in this plant?
2c. What is the effect of taxol on cancerous
tumors? In what way is this effect similar to
the function of taxol in the plant?