Molecules of Life

Carotenoids

October 6, 2011 in Plants

On Friday, December 5th, 2008, the combined English and French fourth grade classes taught by Ms Reavell and Ms Breton at École F.A.C.E. School were exposed to the wonderful world of natural color as they were introduced to the carotenoids and vitamin A, thanks to university students Jess Aylsworth (BA Art Education, Concordia U), Tanya Godina (MSc., U. Montréal), Maya Grubisic (BA Art Education, Concordia U), and Zac Kenny (BA Art Education, Concordia U). First, we reviewed what we had learned about sulfur and bonding from the MLP last Friday. The students were quick to identify the presence of sulfur in foods and one student even described accurately hydrogen-bonding between two water molecules. Tanya and Maya led the class from talking about weak bonds that could be changed by heat to weak bonds that can be changed by light energy as we entered into a bilingual discussion of the carotenoids.

The students were quick to identify that the carotenoid, carotene was present in carrots which were a good source of vitamin A, which Tanya explained was produced from carotene in the body and is used by the eyes to see. Four student volunteers attired in proper lab-wear then performed chromatography on paper and glass plates coated with a thin layer of silica gel to see if the carotene in carrots could be identified in spinach. The students ground up the vegetables and with a little acetone, they extracted enough sample to spot slightly above the bottom of their paper and plates. The spotted paper and plates were then placed in chambers containing a solvent which eluted the color spots up the plate.

As discussed, the spinach too possessed a yellow color spot which moved up the plate faster than the green chlorophyl to the same distance as the yellow carotene spot from carrots. Hence, there seems to be carotene in spinach too. The students recognized that in Fall, leaves change colors as chlorophyll production slows to a halt and eventually all the chlorophyll is destroyed, unmasking the yellow, orange and red colors of the carotenoids. Noting the importance of the carotenoids in absorbing light to provide color and vision, the students made their own light catchers by employing different colored cellophane in a transparent collage. We thanked Team Caratenoid for their illuminating presentation.

Tags: Carotenoids
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Titan and Europa

October 6, 2011 in Space

On Wednesday, April 1st, 2009, the Molecules of Life Project voyaged “where no one has ever gone before” to the moons of Saturn and Jupiter stopping on Titan and Europa. Guided by Université de Montréal Chemistry BSc student Alexandra Cadar and Concordia University Bachelor of Art Education student Catherine Chen, Ms Schuster’s 3rd grade class from École FACE School toured these moons in search of extra-terrestrial life forms, or at least the astrochemistry that suggests that there may be life there someday in the future. Alexandra and Catherine led an interesting discussion on the atmosphere and chemical compositions of the moons and a comparison with those of Earth. The students knew a lot about what is necessary for life on earth. They were fascinated to learn that Europa consists of a smooth white ice outer crust under which lies an expansive and very deep salt water ocean that surrounds a mineral core. They recognized that water and oxygen, which are found on Europa, are essential for life. Titan, they were told may resemble Earth several billion years ago, possessing simple organic molecules such as methane and volcanoes that spew “lava” containing water and ammonia. They were interested to learn that the atmosphere on Titan consists almost entirely of nitrogen which is also the most abundant gas of the atmosphere of Earth (78% nitrogen and 21% oxygen). But, how do scientists know what is on these moons which are hundreds of millions of miles away? ”Spectroscopy” (the study of the interaction between electromagnetic radiation and matter) was described as the tool astrochemists use to study the moons, and the students showed their basic knowledge of radio waves, microwaves for heating, cats that see in the infra-red, the rainbow colors of the visible spectrum and X-rays which they had taken when they broke their bones. With six volunteers, Alexandra showed that some molecules like caffeine which appeared white in visible light, glowed violet under a UV lamp. Catherine then showed how the students could make a model of these moons using a grape for their core, jello of various colors to represent the compositions of the different atmospheres and a glass bowl for the icy outer crust. Sculpting with jello, searching on maps of Saturn and Jupiter for the locations of their different moons and examining the spectrum observed for each moon, the students were very thankful to experience more astrochemistry care of Team Titan and Europa.

For more info and facts on Titan and Europa see: http://www3.signonsandiego.com/stories/2009/mar/16/1c16moons191744-moon-eyed/

What is the composition of jello, a hydrogel of edible proportions see: http://van.physics.illinois.edu/qa/listing.php?id=487

Tags: Europa, Titan
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Moon

October 6, 2011 in Space

Thursday the 3rd of December, 2009, Ms Breton’s 3rd grade classes at École FACE School took a trip to the moon, piloted by MoL Team Moon Science, Joanna Mansour (M.Sc. student, Sociology, U Montréal) and Dr. Tarek Kassem (Post-Doctoral Fellow, Chemistry, U Montréal). Aided by a series of videos (see URLs below), Tarek and Joanna engaged the students in an interactive discussion featuring the many faces of the moon, the theory of its creation, Galileo, Neil Armstrong and of course moon composition, which although it is not made of cheese, like cheese, is rich in calcium. On re-entry to Earth, Tarek mentioned the importance of friction, the force resisting the motion of solid surfaces, and how the friction of the earth’s atmosphere slows down the space ship creating heat. The students were then asked to feel the heat created by the friction of rubbing their hands together. They examined fluid friction by observing the speed of beads dropped into solutions of different viscosity (oil and water). Sliding a block along books with different surfaces, the students recognized that rough surfaces, which have a higher coefficient of friction, slowed the motion of the block better than smooth surfaces. Bringing concepts about the moon and friction together, Joanna taught the students how to moon walk like Michael Jackson. The moon walk was performed with and without shoes to examine which surfaces caused the least friction and best allowed the dancer to glide appearing to float without friction as if on the moon. Exploring friction by rubbing their hands together, clicking their fingers together and moon walking, the students enjoyed being choreographed to dance in ways that were both fun and educational. After one more moon dance with MoL, the students thanked team moon science for a fantabulous lunar experience.

For a video on the phases of la Lune see:

http://www.youtube.com/watch?v=H9Qe6Nh8JJw&feature=related

For a video on the distance to travel to go to the moon and the composition of the moon, see:

http://www.youtube.com/watch?v=_-rvlvuR2zw&feature=related

For a video on les éclipses, see:

http://www.youtube.com/watch?v=8kt4s4PH-GA&feature=related