The diversity of life is staggering. Yet the molecular logic of life is simple and elegant: Small molecules common to all organisms are ordered into unique macromolecules. Explain why carbon is central to this diversity of organic molecules. How do carbon skeletons, chemical groups, monomers, and polymers relate to this molecular logic of life?

VISUAL SKILLS Visualize the structural formula of each of the following hydrocarbons. Which hydrocarbon has a double bond in its carbon skeleton?a. C3H8b. C2H6c. C2H4d. C2H2

VISUAL SKILLS Identify the asymmetric carbon in this molecule:

VISUAL SKILLS Which of the molecules shown in question 5 has an asymmetric carbon? Which carbon is asymmetric?

DRAW IT Draw Lewis dot structures for each hypothetical molecule shown below, using the correct number of valence electrons for each atom. Determine which molecule makes sense because each atom has a complete valence shell and each bond has the correct number of electrons. Explain what makes the other molecule nonsensical, considering the number of bonds each type of atom can make. b.

Which molecule has the shape of a completed tetrahedron?

Which of the following is an organic molecule?

Using modern equipment, a former graduate student of Stanley Miller recently reanalyzed the sample results of volcano simulation experiments that Miller conducted along with his classic experiment described in the text. This reanalysis did which of the following?