Taxol

October 6, 2011 in Plants

On Wednesday, November 19th, 2008, the students in Mrs Shuster’s third grade class at École F.A.C.E. School were extracting natural products from plants and using their powers of perception to identify them, thanks to university students Alexandra Cadar (B.Sc., U. Montréal) and Julia Waks (BA Art Education, Concordia U).  Alexandra and Julia engaged the class in a discussion on plant derived products.  As an example, slices of aloe-vera were cut and distributed to the students to present an example of a beneficial plant because of its powers to treat burns and wounds.   Similarly, vitamin C was mentioned as an essential nutrient for good health, obtainable from lemons and oranges.  After refreshing the students memory on proper safety attire, three volunteers performed extractions of three samples of different leaves by pipetting hot water over each and collecting the colored extracts.  Using their sense  of smell and examining the color, the students were able to identify the leaf samples from cranberry, camomile and mint.  A discussion of the medicinal attributes of these plants followed.

Alexandra and Julia introduced next the molecule of the day “Taxol” which is extracted from the bark of the Yew tree.  Yew trees, are evergreens that can look like Christmas trees.  They are slow growing, some are estimated to be as old as 4,000 years. Yew trees are difficult to start from seed, because they germinate only after passing through the gut of some animal, such as an elk or deer.  Native American Indians used the wood from the Yew tree to make archery bows and paddles, Europeans used it to make musical instruments. About 40 years ago, scientists studied and tested the different parts of the Yew tree and discovered that the bark of the tree and some other parts of the tree contained an active molecule, that they named “Taxol”.  Taxol is now used as a medicine to fight cancer.  The students related their own stories about their interactions with family and friends with cancer, which led to a deeper discussion about this disease and the application of taxol as a cure. Finally, considering the many rings in the structure of taxol, the students made collages featuring rings on the front-side of get-well cards to be delivered to children with cancer at the Montreal Children’s Hospital.

The 3rd graders and all thanked team taxol for their thought provoking and sensitive presentation of the wonders and benefits of plant natural products.

Alexandra Cadar (B.Sc., U. Montréal) and Julia Waks (BA Art Education, Concordia U) leading a discussion on plant-derived products.TACJWclass[1].jpg ¬

Note last week, as mentioned in our MLP on Taxol, the students made collages featuring rings on the front-side of get-well cards, that were delivered to children with cancer at the Montreal Children’s Hospital.  As Julia Waks from Team Taxol writes:

“Attached are the photos taken at the Montreal Children’s hospital. The “absolutely adorable get well cards” were very well received by the staff at both the haematology out patient clinic as well as the 8th floor oncology ward. Mrs.Terry Seguin, head of communications at the hospital, (in photo)and other staff members were very enthusiastic and helpful. The cards look great and will be much appreciated by the kids, parents and staff. Bravo to all the kids for a job well done.”

Chlorophyl

October 6, 2011 in Plants

On Wednesday, November 12th, 2008, the students in Mrs Shuster’s third grade class at École F.A.C.E. School shined, radiating with knowledge of “chlorophyl” provided by  university students April Clyburne-Sherin (BA Art Education, Concordia U.) and Vanessa Kairouz (B.Sc., U. Montréal).   April and Vanessa led the students through the cycle of respiration and photosynthesis explaining how animals take in oxygen and sugar producing carbon dioxide and water which the plants take in to produce oxygen and sugar.  Chlorophyl was presented as the molecule that harnesses energy from light for the conversion of carbon dioxide and water into oxygen and sugar.  Employing spinach leaves, the students were led through an extraction which started with everyone tearing up leaves and finished by students in proper lab-attire using rubbing alcohol (iso-propanol) and water to extract out the green colored chlorophyl.  Employing the extract as paint, the students then painted pictures of their favorite food.  The pictures were next examined under a black light bulb and appeared to luminance an orange red colour. April and Vanessa explained how under blacklight the chlorophyll reacts with light absorbing its energy and later releasing the energy by glowing and producing heat.

Using modern dance to help the students interpret the relationship between the molecules in the photosynthesis and respiration cycles, team chlorophyl inspired students to behave as molecules by exchanging cards containing their atoms as they converted themselves from oxygen and sugar to carbon dioxide and water and back again.

Illuminated like chlorophyl, we all thanked team chlorophyl for shining some light on the wonders of photosynthesis and plant chemistry.

Note: the chloro portion of the word is from the Greek chloros, which means yellowish green. The name of the element chlorine also comes from the same source. Chlorine is a yellowish green gas. There is no chlorine in chlorophyl, but there is magnesium.

For more information see: http://scifun.chem.wisc.edu/CHEMWEEK/CHLRPHYL/Chlrphyl.html

For chlorophyl experiment see:

http://c-lab.co.uk/default.aspx?id=9&projectid=58

 

Cellulose

October 6, 2011 in Plants

Like a tree, Molecules of Life grew into its 4th academic year, thanks to that the ever popular, multi useful , abundant natural product, cellulose, which was presented to Ms Sanchez’s 3rd grade class at École FACE School on Wednesday the 18th of November, 2009, by MoL Team Cellulose, Kim Beauregard (MSc student U Montréal) and Diana Rodriguez (Master student of Art Education, Concordia).   Introducing cellulose, as a linear chain of sugar units , a principal component of cotton (90%) and wood (50%), Kim was pleased to see the students identify the many items made using this versatile polymer: clothing, paper, desks, chairs, the classroom door… and mentioned further the presence of cellulose in the thin transparent film, cellophane and the semisynthetic textile, rayon.   For comparison, Kim also introduced starch, another polymer of sugar (glucose), which because of a difference in chemical linkage geometry adopts a spiral structure, instead of the linear cellulose strand.

The students then ground up a series of food samples (banana, celery, potato and bread) and compared them with sugar in a starch iodine test.  After a brief discussion of lab safety, three students put on lab coats, lab glasses and gloves, and performed the test which produces a dark blue-black color in the presence of starch, the helical structure of which enwraps the iodine.

The utility of starch as glue for binding paper fibers was next demonstrated by Diana, who taught the students how to recycle paper. Shredding old newsprint, cardboard and old note paper, the students then watched their shredding mix in a blender with some corn starch to form a paper paste which they applied to screens to produce new sheets of hand-made recycled paper.

Discussing cellulose and starch, the students learned that although cows and termites can eat wood, it is the symbiotic micro-organisms that live in their guts, which allow these animals to digest the cellulose into the sugar needed for energy.  On the other hand, humans cannot digest cellulose, which serves as ‘fiber’ to help digestive flow.

Happy to do some first hand recycling, the students thanked team cellulose for exposing them to the many products and properties of this key component of many of life’s simple comforts and food,

 

For more information about cellulose see: http://en.wikipedia.org/wiki/Cellulose

For more on the Starch – Iodine test see: http://www.elmhurst.edu/~chm/vchembook/548starchiodine.html

Resource for teachers about cellulose : http://moleculesoflife.ca/?p=931