Enzyme Catalysis

The following experiments demonstrate the nature of enzymes and their respective substrates, with an emphasis on biochemistry. The hands-on Enzyme Catalysis I demo uses toothpicks and the participants' hands to show temperature effects on enzyme-substrate interactions. Enzyme Catalysis II uses pineapple and jello to demonstrate the properties of digestive enzymes. Each demo should take ~30 minutes.

Enzyme Catalysis I.doc

Enzyme Catalysis II.doc

Enzyme Catalysis III.doc

Polymer Chemistry

Polymers are large cross-linked molecules made up of repeating structural units. They exist artificially as plastics and naturally as DNA, RNA, and proteins. This activity has the participants act as molecules to demonstrate the effects of temperature and cross-linking. It also uses sodium silicate and ethanol to create a gooey polymer ball (~30 minutes).

Polymer Chemistry I.doc

Redox Chemistry

Redox-oxidation reactions are any chemical reactions that occur when the oxidation state of atoms change. Oxidation is the loss of electrons and reduction is the gain of electrons. One example of a reduction reaction is the tarnishing of silver. This experiment uses hard boiled eggs to tarnish silver and baking soda to reverse the process.

Redox Chemistry.doc

Electron Orbitals

Atoms are made of protons, neutrons, and electrons. The electrons orbit the atom in spaces called orbitals. Additional electrons move in orbitals with increasing average distance from the atom's nucleus. These demonstrations explore the effects of the increased average distance. The Rubber Chicken demonstration shows that an electron jumping from one orbital to another undergoes a specific change in energy. This energy is released as light and turns a Bunsen burner flame different colors. The Periodicity demonstration shows that electrons in higher orbitals are held more loosely and can therefore be removed from the atom more readily. The result of this phenomenon is that calcium metal reacts much more quickly with water than magnesium.

Rubber Chicken.doc

Periodicity.doc

Density

Density is defined as the amount of mass contained in an object per unit volume. The density demonstration contains two experiments that demonstrate how differences in density cause objects to float. The first experiment uses carbon dioxide to cause raisins to float and sink like submarines. Normal raisins collect and hold more carbon dioxide bubbles and therefore float more frequently than chocolate covered raisins because they become less dense. The second experiment uses solutions of glycerol mixed with water to create a liquid rainbow. Glycerol is more dense than water; therefore, mixing different amounts of glycerol and water creates solutions with different densities. When food coloring is added, and the solutions are stacked in order of density, the students will have created a liquid rainbow.

Density.doc