1. Write the structure of a general triglyceride. Specify the kinds of carboxylic acids which are typically present in such triglyceridesWrite the structures of palmitic, stearic, oleic, and linoleic acid. Be sure to specify the geometry of an double bonds present.
2. What strucural features distinguish fats from oils? What does the geometry of the C=C bonds have to do with the physical state of the triglyceride?
3. What is the name of the C20 unsaturated fatty acid which is the precursor of prostaglandins?
4. Write the structure of one phospholipid. How are phospholipids used in the cell? What is the name given to the type of structure formed by phospholipids.
5. Show a chemical equation for the formation of soap from triglycerides. Explain how soap functions, depicting and naming the fundamental type of structure formed by soaps in aqueous solution.
6. Explain why carboxylate salts having shorter or longer hydrocarbon tails than those found in natural fatty acids are not effective as soaps.
7. Write the structures of two common household detergents and sketch their syntheses. In what respect are these detergents superior to soap?
8. How many carbon atoms are present in a terpene? In a sesquiterpene? In a diterpene? A triterpene? A tetraterpene?
9.What important carboxylic acid is the immediate precursor of isopentenyl pyrophosphate? Write the structure of isopentenyl pyrophosphate. Also, write the structure of the pyrophosphate moiety of isopentenyl pyrophosphate.
10. Sketch the mechanism for the conversion of isopentenyl pyrophosphate to geranyl pyrophosphate. Specify the roles (nucleophile/electrophile) of both isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate(DMAP) in this mechanism. Explain why each is particularly suited to its role (allylic resonance, leaving group ability, steric effects, and formation of a tertiary carbocation should all be considered).
11. Sketch the mechanism for the conversion of geranyl pyrophosphate (GPP) to limonene.
12. Sketch the mechanism for the conversion of GPP to farnesyl pyrophosphate (FPP).
13. What substance is the immediate precursor of steroids? How is this precursor formed?
14. Draw the skeletal structure common to steroids. Draw the conformational structure of this fused ring system (chair forms, etc.).