5. According to the Aufbau Principle, which of the following energy sublevels will be filled with electrons after 3p is filled with electrons? а. 3s d. 4p b. 3d е. 4d С. 4s f. 4f

C) NUCLEIC ACID Sketch the general structure of a nucleic acid monomer and name all characteristic chemical groups: TETAAL Sketch the general structure of a nucleic acid polymer and name all characteristic chemical group: Name of bond between monomers: D) LIPID Sketch the general structure of a triglyceride molecule, name the characteristic chemical groups that form the molecule, and label the chemical linkages between the groups: inte imveneg Sketch the general structure of a phospholipid molecule, name the characteristic chemical groups that form the mol- ecule, and show how phospholipids align to create cell membranes. Name the characteristic that distinguishes all lipids from other large molecules:

2. A protein is a polymer of amino acids that assume a unique structure in space primarily using intermolecular forces. Identify/circle the IMF that give protein structure in the following picture. Briefly describe these key IMFs. 198

A circular double-stranded DNA molecule contains 4200 base pairs. In solu- tion the molecule is in a B-form helix, with about 10.5 base pairs per turn. The DNA circle has 12 superhelical turns. What is its superhelix density o?