"A bear is wiser than a man because a man does not know how to live all winter without eating anything." Abenaki (People of the Dawn) saying. This is the third post describing the metabolic and nutritional chemistry of bear hibernation.
I came across an interesting Journal of Chemical Education article that explains how it is possible to crosslink sodium alginate, leading to the formation of calcium alginate beads. Calcium alginate beads are hydrogels and one of their uses is to immobilize enzymes in their structure. I thought it would be cool to immobilize some lactase enzyme onto calcium alginate beads and investigate its ability to hydrolyze lactose.
I’ve always been fascinated by advanced polymeric materials; it’s amazing how materials that are generally considered “plastics” have such stunning properties. I recently watched a couple of movies about Batman and it came out that some of his devices and protections are made of advanced polymers. In particular, the suit is almost entirely made of Kevlar.
Are you up for trying an ambitious experiment that combines archeology, instrumental analysis, and a search for patterns in data? Then this activity might fit the bill!
What happens if you cool a Scrub Daddy sponge in liquid nitrogen (or dry ice) and subsequently strike it with a hammer? Let's find out!
The recently published iPad app ChemTube3D (and related website for classrooms without iPads) will be discussed. It has a great deal of functionality - including a large selection of organic mechanism animations and models of structure and bonding.
Heidi Parks offers a soap-making lab or activity that can be run in a chemistry class with 25-30 students working at the same time. She usually does this activity right before spring break, as it provides enough time for the soap to harden and cure (high school students are impatient to use their soaps right away, which you should not do with cold process soap). She has used this soap making activity at different points in the curriculum: during intermolecular forces during acids and bases, and during stoichiometry.
For a recent unit on organic chemistry for my IB students, I tried something new. I gave them a handout with a list of organic compounds (by class/functional group) and a list of mechanisms and reaction types. Their task (in small groups), using either butcher paper or a large whiteboard, was to create a flow chart of reaction pathways.
Students will build models of isomers while the instructor walks around from station to station to critique the models. If the model is incorrect, the students rebuild until they get it right. The paper that accompanies this assignment is very easy to grade.
I have used several different versions of the Silver Mirror or Tollen's Test lab. I am sharing the method that has proven to be the most reliable for me. The solutions should be made fresh, the directions must be followed closely and timing is very important. I like the fact that relatively small amounts of the chemicals are required, but as always you must be vigilant with safety precautions.