Lesson+on+Energy+for+Biochemistry+Unit

Activities on Energy

The demos here are of course only one possibility. There are many alternatives that accomplish the same idea.

1. Discussion of mechanical energy

This is done first because it is easiest to visualize. Throw a ball, and prompt students about energy. Then, place it in a slingshot, and do the same. Then, allow a cart to brought to rest by a magnet, and ask where the energy went. Ask them to prove this to you, and they prompt you to release it. And so on. Develop concepts of kinetic and interaction energy, reinforce the idea that energy is conserved. Then, introduce pie and bar charts, and do problems like WS1a from the workshop.

2. Discussion of thermal energy and energy transfer

Allow a bowling ball to roll to a stop, ask where the energy went. Compare to cart on low-friction track. Probe for specifics, develop molecular motion model of thermal energy, and remind them of connection to temperature. Then discuss energy transfer processes - by pushing (work) and by a temperature difference (tiny collisions; heat). Then do parts of WS1b.

3. Discussion of chemical energy

Discuss the bonding process, including diagrams or simulations. Ask what causes the molecules to become bound? (A force, or an interaction.) No need to discuss the nature of the force; only need note that it is attractive. Make the explicit analogy to gravitation. Ask what is happening to energy in this process, and accompany the discussion with gravitation demonstrations (allow a weight to fall; then lift it again). Get at what happens in terms of energy when bonding or unbonding occurs; introduce Ech, and bar graphs. Importance of thermal energy / activation energy. Do WS1c.