Chapter 2: The Chemical Context of Life Objectives The student is responsible for: 1.The definitions of all bold faced words in the chapter 2.Knowing the entire chapter especially: a)The different kinds of chemical bonds: polar covalent, nonpolar covalent, ionic, hydrogen, Van der Waals or dispersion forces. b)Hydrogen bonds are extremely important. Be able to draw, write out and identify hydrogen bonds that exist between two identical molecules (water – water) or two different molecules (water-ammonia).

3.This chapter should be a review for you. Do not expect me to spend much, if any time on this. 4.If you have questions about this material, you really should come in and ask me to explain what you help on. There’s nothing wrong with asking for help. It’s just that I don’t want to take up class time because most of you probably recall most of this material. I’d rather be teaching other material. 5.Use the following slides on which to take notes as you read. 6.Use the Chapter Outline also for note taking.

Figure 2.1 The hierarchy of biological order from atom to organism

Table 2.1 Naturally Occurring Elements in the Human Body

Figure 2.5 Two simplified models of a helium (He) atom

Figure 2.9 Energy levels of an atom’s electrons This is a very important concept. Be sure you know it.

Figure 2.12 Covalent bonding in four molecules

Figure 2.13 Polar covalent bonds in a water molecule This is a very important diagram Be able to draw it in your sleep..

Figure 2.16 A hydrogen bond Be able to draw and label the bonds in this type of diagram.

Figure 2.18 Molecular shape and brain chemistry

Figure 2.19 A molecular mimic

Unnumbered Figure (Page 38) Chemical reaction between hydrogen and oxygen Energy is required to break bonds in the reactants and energy is released when new bonds are made as the products form.